Volcano Profile: Glacier Peak

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Location: Snohomish County, WA

Elevation: 3,213 m (10,541 ft)

Nearby towns: Darrington

GEOLOGY

Sitting relatively low on the skyline, Glacier Peak is mostly hidden from Puget Lowland residents, yet it is one of the more dangerous of the Cascade volcanoes. The volcano frequently and explosively produces dacite lava flows, tephra (ash) and far-reaching lahars (volcanic mudflows).

Geologic mapping has documented the extent of previous lahar runout in the Skagit and Stillaguamish river valleys. While Glacier Peak has shown no sign of eruption in the last few decades, lahar deposits in river valleys from past eruptions are reminders of the hazards Glacier Peak poses to nearby communities.


Lahar hazards are determined in part by figuring out where lahars traveled in the past. Evidence of massive lahars is abundant in many of the valleys that drain Glacier Peak. The above map shows the distribution of lava flows and lahars mapped at the surface. Volcanic hazard areas are shaded gray. Much of the past volcanic deposits have been either eroded or buried by rivers, glaciers or human development.

ERUPTION AND LAHAR HISTORY

Glacier Peak erupts frequently. The eruptions are typically explosive and occasionally voluminous. Most eruptions involve tephra, but many were accompanied by far-reaching lahars and dome-building.

Glacier Peak has erupted multiple times in the last 15,000 years. About 13,000 years ago, a series of large tephra eruptions occurred, accompanied by numerous lahars—one eruption was many times the size of the Mount St. Helens 1980 eruption. Within the last 5,000 years, the volcano produced frequent lava dome eruptions and subsequent dome collapse and lahars. The most recent eruption was only about 300 years ago.

Are You Volcano Ready?

  • Get to know your local volcano’s hazards
  • Register for notifications about the volcano’s activity
  • Make a plan to prepare your entire family for an emergency

Links

Visit the USGS website for more information on how to be volcano ready, view interpretive signs, and find lahar evacuation routes.

Click on the image (left) for a link to the poster.

 

 

Further Reading

Dragovich, Joe D.; McKay, Donald T., Jr.; Dethier, David P.; Beget, James E., 2000, Holocene Glacier Peak lahar deposits in the lower Skagit River Valley, Washington: Washington Geology, v. 28, no. 1/2, p. 19-21, 59. 

 

 

 

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Volcanic-Hazard Zonation for Glacier Peak

 

 

Local Resources

          

Hot Out of the Mantle…

Today, DGER brings you three new volcano-related resources:

  1. Volcano hazards are now on our portal and available in GIS format
  2. We have a new volcanoes webpage — you’ll lava it!
  3. We’ve just released a series of posters for Volcano Preparedness Month.

ger_pubs_data_portal_tile_240x170Portal Update

A new layer is now available on our Geologic Information Portal. The Volcanic Hazards layer provides a simplified version of data modified from the USGS. The data includes: hazard type, description of hazard, and steps to follow in an emergency. You may also download the GIS data from our GIS Data and Databases page, or directly here.

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Suggested citation:

Washington Division of Geology and Earth Resources, 2016, Volcanic hazards, adapted from U.S. Geological Survey–GIS data: Washington Division of Geology and Earth Resources, version 1.0, May, 2016.

New Webpage

Check out the all new sections of our updated Volcanic Hazards webpage:


Washington volcanoes

Volcanic hazards

Evacuation and
preparation

Volcano hazard
information map

Understand
volcanoes

What we do

Volcano preparedness
posters

Fun volcano
activities

Volcano Preparedness Posters

In cooperation with the U.S. Geological Survey and several Emergency Management Departments from local counties, we have developed a series of posters to promote awareness of the hazards posed by Washington’s five active stratovolcanoes.

These posters are available for download on our newly updated Volcanoes and Lahars page of our website or click the links below:

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Stay tuned for two more weeks of Volcano Preparedness Month!

Volcano Profile: Mount St. Helens

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Location: Skamania County, WA

Elevation: 2,549 m (8,363 ft)

Nearby towns: Castle Rock, Olympia, Vancouver, Portland (OR)

GEOLOGY

Mount St. Helens produces dacitic to andesitic lava flows, pumice, and lahars. Like Glacier Peak, the composition of its magma makes it erupt more explosively than other Cascade volcanoes that erupt andesitic lava.


The areas prone to lahars are determined in part by figuring out where lahars traveled in the past. The map shows the distribution of lava flows and lahars mapped at the surface compared to hazard zones (gray shaded areas). Evidence of repeated eruptions can be found in many of the valleys that drain Mount St. Helens.

ERUPTION AND LAHAR HISTORY

Mount St. Helens was formed from four eruptive stages starting ~275,000 years ago, and intermittent eruptions occur to this day. During one such eruption around 2,000 years ago, lava flowed down the side of the volcano in streams, one stream formed the Ape Caves, a spectacular 13,042-foot-long lava tube on the southeastern flank of the volcano.

1980 Eruption

From March 16 to May 18 in 1980, a series of earthquakes, steam explosions, and small eruptions at the summit signaled a new eruptive phase of the volcano. By mid-April of 1980, a large bulge of new volcanic material had formed on the north flank of the mountain and moved outward at an average rate of ~5 feet per day.

On May 18th, the cataclysmic eruption was triggered by a magnitude 5.1 earthquake. The bulge collapsed in a series of three massive slide blocks. This bulge collapse generated a chain reaction, starting with the largest avalanche in recorded history (0.6 cubic miles of material, reaching speeds of 60 miles per hour). The removal of this material decreased the pressure holding back the magma and caused the release of gas, large rocks, and smaller particles that moved across the landscape and destroyed most vegetation at an astounding speed of 650 miles per hour. This initial blast caused major lahar flows, pyroclastic flows, and an ash eruption that formed a eruption column 12 miles high and 45 miles across.

In addition to ash, pyroclastic flows and lahars traveled swiftly across the Pumice Plain and down the North Fork Toutle and Cowlitz Rivers, destroying houses and bridges along the way.


Time-lapse reconstruction of the lateral blast, courtesy of Joseph Friedman.

2004 Dome Building

In September of 2004, earthquake swarms, minor explosions, and lava dome growth were observed in the summit crater. For the next 3+ years, lava continued to build up in the crater and generated a lava dome that is 1,500 feet high. This activity continued steadily until late January of 2008.

Mount St. Helens is located along a 65-mile-long zone of intense earthquake activity called the St. Helens seismic zone. Many small to moderate (up to 5.5) magnitude earthquakes occur in this area. Geologists monitor the earthquake activity very closely to look for signals of another eruption.


Sequential lidar imagery of dome building at the summit of Mount St. Helens. Imagery collected between 2002 and 2004.


Time-lapse images of Mount St. Helens dome growth (2004–2008).

Are You Volcano Ready?

  • Get to know your local volcano’s hazards
  • Register for notifications about the volcano’s activity
  • Make a plan to prepare your entire family for an emergency

Local Resources

Visit the USGS website for more information on how to be volcano ready, view interpretive signs, and find lahar evacuation routes.

Click on the image (left) for a link to the poster.

 

Further Reading

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USGS Volcanic-Hazard Zonation for Mount St. Helens

 

 

 

Pringle, Patrick T., 2002, Roadside geology of Mount St. Helens National Volcanic Monument and vicinity; rev. ed.: Washington Division of Geology and Earth Resources Information Circular 88, 122 p.

 

 

 

The Ring Of Fire

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Figure by USGS

Volcanoes usually form at the boundaries of tectonic plates (where the Earth’s crust moves apart or collides). The Ring of Fire is a 25,000-mile long horseshoe-shaped “ring” that circles the Pacific Ocean. It is called the Ring of Fire because that is where most of Earth’s volcanoes are found.

The Ring of Fire is also a Johnny Cash song, to which geologists love to make their own silly volcano parodies.

There are 452 volcanoes in the Ring of Fire, and it is home to 75% of the world’s volcanoes and about 90% of the world’s earthquakes.

Check out the Storymap below to learn more about the Ring of Fire, and see some of the major volcanoes around the world that are a part of it:

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3D Story Map about the Ring of Fire, by Esri. View in fullscreen.

Volcano Profile: Mount Baker

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Location: Whatcom County, Washington

Elevation: 3,286 m; 10,781 ft

Nearby Towns: Glacier, Concrete

GEOLOGY

ger_hazards_volc_baker_geo_map.pngMount Baker produces andesitic lava flows, pumice, and lahars.The areas prone to lahars are determined in part by figuring out where lahars traveled in the past. Evidence of massive lahars is still abundant in many of the valleys that drain Mount Baker. The map shows the distribution of lava flows and lahars mapped at the surface compared to hazard zones (gray shaded areas). Much of the volcanic deposits have been either eroded or buried by rivers, glaciers, and human development.

ERUPTION AND LAHAR HISTORY

Mount Baker is one of the youngest Cascade volcanoes, and erupts less frequently. Its last major eruptive period occurred about 6,600 years ago, where large portions of the flank repeatedly collapsed generating massive lahars. There are additional reports of eruptions and lahars from the 19th century, and as recently as 1975, fumarole activity and snow melt ramped up dramatically for several years.

Eruption and Lahar history of Mount Baker

Steam and gas still issue from both Sherman Crater and the Dorr fumarole field on the northeast flank of the volcano today. Mount Baker holds the world record for most snowfall in a single season—95 feet in 1999!

Short visual tour of Sherman Crater, Mount Baker summit fumarole field. Video by Dave Tucker.

Are You Volcano Ready?

  • Get to know your local volcano’s hazards
  • Register for notifications about the volcano’s activity
  • Make a plan to prepare your entire family for an emergency

Local Resources

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Visit the USGS website for more information on how to be volcano ready, interpretive signs, and lahar evacuation routes.

Click on the image (left) for a link to the poster.

 

Further Reading

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Potential Volcanic Hazards from Future Activity at Mount Baker 

 

 

 

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 Mount Baker-Living with an active volcano

 

 

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Volcano Profile: Mount Rainier

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Location: Pierce County, WA

Elevation: 4,392 m; 14,410 ft

Nearby towns: Orting, Seattle, Tacoma, Yakima

ger_hazards_volc_rainier_geo_map.pngGeology

Mount Rainier produces andesitic and dacitic lava flows, pumice, and lahars.

The areas prone to lahars are determined in part by figuring out where lahars traveled in the past. Evidence of massive lahars is still abundant in many of the valleys that drain Mount Rainier. The figure at right shows the distribution of lava flows and lahars mapped at the surface compared to hazard zones (gray shaded areas). Much of the volcanic deposits have been either eroded or buried by rivers, glaciers, and human development.

ERUPTION AND LAHAR HISTORY

Modern Mount Rainier started erupting only 500,000 years ago with intermittent eruptions and mudflows thereafter.

Mount Rainier still issues steam and gases from fumaroles near the summit crater, which melt the snow and ice at the crater, as well as melt the summit icecap, forming caves beneath the ice.

Researchers study earthquake activity in the Mount Rainier area to learn about the background seismicity, or the small day-to-day earthquakes, that occur in the crust as magma below the volcano shifts and faults in the area move to accommodate fluids and gasses produced by the magma.

By studying the earthquakes, geologists can monitor increases in seismicity (earthquakes) to hopefully be able to tell if the volcano is about to erupt. Geologists are particularly interested in a large north-trending fault zone west of Mount Rainier, called the Western Rainier Seismic Zone, which is an area of dense and shallow earthquakes.

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Eruption and lahar history of Mount Rainier

Osceola and Electron Mudflows

5,600 years ago, a massive debris avalanche, called the Osceola Mudflow, poured down from the summit of Mount Rainier, picking up sediment and anything else in its path as it traveled down the White River valley and into the Puget Sound. The mudflow filled valleys with ~400 feet of sediment and moved at speeds of 40 to 50 miles an hour. Following the Osceola Mudflow, many smaller volcanic eruptions and lahars occurred as the volcano continued to show signs of unrest.

The last major mudflow, called the Electron Mudflow, began as a part of a crater collapse and traveled down the Puyallup River into Sumner in ~1503.

It is estimated that Mount Rainier has generated about 60 of these lahars in the last 10,000 years. Many of the communities between Mount Rainier and the Puget Sound are built right on top of these deposits.

Are You Volcano Ready?

  • Get to know your local volcano’s hazards
  • Register for notifications about the volcano’s activity
  • Make a plan to prepare your entire family for an emergency

Education Resources

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Visit the Opportunities for Educators webpage by clicking the image at left. To access USGS volcano teaching materials or posters click here.

 

 

Local Resources

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Visit the Pierce County website for more information on how to be volcano ready, interpretive signs, and lahar evacuation routes.

Click on the image (left) for a link to the poster.

 

 

Further Reading

      

Volcanic Hazards from Mount Rainier

Living With a Volcano in Your Backyard

Digital Data for Volcanic Hazards from Mount Rainier

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Types of Volcanoes

Are all volcanoes alike? While many people think of a volcano as cone-shaped mountain that spits red hot lava and has a plume of ash like the one shown below, in fact, there are multiple types of volcanoes.

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The shape, size, and lifespan of a volcano depends on its location (under the ocean, at a convergent plate boundary, a hot spot etc.), the chemistry of the magma that erupts from it, and the amount of ash and lava in the eruption. Depending on the chemistry of the magma, the volcano can erupt either explosively or non-explosively; the style of eruption also affects the overall shape of the volcano.

While other types exist, there are three main types of volcanoes. They are cinder cones, composite volcanoes (stratovolcanoes), and shield volcanoes.

 

CINDER CONES


Diagram of a cinder cone, modified from image on DKfindout.

Cinder cones, the simplest type of volcano, are steep cone-shaped hills made up of cooled, air-filled lava, called cinder or scoria (commonly referred to as lava rock) that were ejected from a single vent. Cinder cones are commonly found near shield volcanoes or stratovolcanoes. Some only erupt once such as the famous Paricutin cinder cone, while others may erupt many times.

COMPOSITE VOLCANOES OR STRATOVOLCANOES


Diagram of a stratovolcano, modified from image on DKfindout.

Composite volcanoes or stratovolcanoes, are typically some of the world’s most beautiful and beloved mountains. All the major Cascade volcanoes including Mount Rainier and Mount St. Helens, as well as Mount Fuji, Mount Vesuvius, and Krakatoa are stratovolcanoes. These beautiful mountains are what most people think of when they picture a volcano—steep-sided, symmetrical cones that typically have a crater at the summit.

Stratovolcanoes can be very tall, many are more than 14,000 feet, and are built from alternating layers of volcanic ash, lava flows, and cinder. A stratovolcano forms from conduits where magma travels from deep within the Earth to the surface through a central vent which connects to multiple radiating dikes and secondary vents. Stratovolcanoes are commonly found at convergent plate boundaries, such as along the edge of the Pacific Ocean within the Ring of Fire.

Stratovolcanoes can erupt explosively (see video below) and can cause great damage to people living near them. The biggest hazard for people living near stratovolcanoes is not from lava, which moves slowly down the volcano, but from lahars (fast-moving volcanic mudflows) that can barrel down the slopes of the volcano at incredible speeds (up to 120 miles per hour!) destroying everything in their path.

SHIELD VOLCANOES


Diagram of a shield volcano, modified from image on DKfindout.

Shield volcanoes are the largest volcanoes in the world. They are called shield volcanoes because when you look at them from afar they resemble a warrior’s shield. Mauna Loa, a shield volcano on Hawaii’s big island is the largest single mountain on earth. It reaches 30,000 feet above the ocean floor and is approximately 100 miles across at its base.

Shield volcanoes have shallow slopes and are made of layer upon layer of cooled lava that flowed down the slope in all directions from a central summit vent, or group of vents. Lava can also erupt from fractures or fissures along the edges of shield volcanoes.

 

What is a Volcano?

ger_hazards_volc_understanding_volcanoesA volcano is an opening in the surface of a planet (or moon) that allows hot material to escape from the magma chamber below the surface. When the hot material, such as lava, ash, and gas make their way to the surface, the volcano erupts. The style of eruption depends on the type of magma. Eruptions can be explosive, sending hot mixtures of ash and gas high into the sky; or they can be calm, only sending small amounts of lava down the slope.

Several factors determine the explosiveness of a volcanic eruption. These include: dissolved gases, water vapor, temperature, and composition. The composition determines the viscosity, or the resistance to flow, of the magma. Magmas with a high viscosity are thick and slow moving, and have a high silica content. Low viscosity magmas are thin and runny, and have a low silica content.

The three types of magma are:

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There are three ways the magma can make it to the surface:


Subduction zones, mid-ocean ridges, and hot spots. Image modified from Nasa SpacePlace.

1) Subduction When tectonic plates bump into each other (converge) one of the tectonic plates can be pushed under another one deep into the Earth under the crust (called subduction). The tectonic plate that was forced into the Earth then melts from the high temperature and high pressure and can eventually rise to the surface as magma and form a volcano from the melted crust. The big volcanoes in Washington are formed this way.

2) Mid-Ocean Ridges When tectonic plates move away from each other (diverge) the hot, buoyant magma beneath the crust rises to fill the space. This typically happens in oceanic crust underwater and forms “black smokers”.

3) Hot Spots The third way that volcanoes can form is at a hot spot inside the earth. Scientists are still figuring out exactly why hot spots happen where they do, but the basic idea is that magma rises and pushes its way to the surface through the tectonic plate. Yellowstone and the Hawaiian islands are two famous examples of hot spot volcanoes.

 

May is Volcano Preparedness Month

3345May is Volcano Preparedness Month, and to prepare we will bring you a different volcano profile each week and provide information on how to prepare for any emergency. Preparing today could save you and your family during the next eruptive event.ger_hazards_volc_hazard_overview_1140.png

Washington has five major volcanoes: Mount Baker, Glacier Peak, Mount Rainier, Mount St. Helens, and Mount Adams. These volcanoes are part of the Cascade Range, a 1,200-mile long line of volcanoes that stretches from British Columbia to northern California. Each of Washington’s five major stratovolcanoes are still active. In fact, all of them except for Mount Adams have erupted in the last 250 years. Volcanoes do not erupt at regular intervals, so it is difficult to know exactly when or where the next eruption will happen. It is important to prepare ahead of time.

Learn about the volcanic hazards where you live, work, and play; make a family emergency plan today!

EVACUATION AND PREPARATION

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Volcanic eruptions and lahars are frightening natural disasters. It is important to prepare ahead of time.

The eruption of Mount St. Helens on May 18, 1980 killed 57 people, destroyed 27 bridges and almost 200 homes, and caused disruption for thousands of people. You can minimize damage and loss of life by being prepared for a volcanic emergency. One of the most important things you can do is learn about your risks.

The following information is synthesized from the Cascade Volcano Observatory, Washington Emergency Management Division, and Ready.gov web sites.

 

BEFORE AN ERUPTION

  • Learn about your risks—Know the danger and hazards you face at home, at work, and where you recreate or travel.
  • Plan ahead. Have emergency supplies, food, and water stored.
  • Plan an evacuation route away from streams that may carry lahars or landslide debris.
  • Make sure your emergency provisions contain a pair of goggles and disposable breathing masks for ash and dust.
  • Make a family emergency plan so that you know how to contact your family members in case of an emergency.
  • Stay informed: Listen to media outlets for warnings and evacuations. Listen for All Hazard Alert Broadcast sirens that warn of lahars. Check out the Volcano Notification Service to subscribe to alerts about specific volcanoes.
  • Ask local and state emergency offices and schools about their response plans. Be prepared to follow official guidance.

Be informed. Make a plan. Build a kit. Educate and protect your family, neighbors, and friends.

DURING AN ERUPTION

    • Follow evacuation orders issued by authorities. Evacuate immediately from an erupting volcano!
    • Be aware that lahars and other types of landslides or debris flows can travel great distances from the volcano. Avoid river valleys and other low-lying areas that may be prone to these hazards.
    • If you are in a lahar hazard zone and become aware of an oncoming lahar, get to high ground and then shelter in place. If there are signed evacuation routes, follow them.
    • Stay informed: Watch and/or listen for additional information.
    • Listen for All Hazard Alert Broadcast sirens that warn of lahars.
    • Do your part to remain safe and help others in need.

IF THERE IS ASHFALL…

Protect your lungs!

Volcanic ash is made of microscopic shards of glass and other fine-grained material. Ash can can cause significant damage to animals, including significant damage to lungs or asphyxiation if inhaled.

      • If there is falling ash and you cannot evacuate, remain indoors with doors, windows, and ventilation systems closed until the ash settles.
      • Help infants, the elderly, and those with respiratory conditions.
      • Wear a respirator, face mask, or a use a damp cloth across your mouth to protect your lungs.
      • Use goggles, and wear eyeglasses instead of contact lenses.
      • Avoid driving in heavy ash fall unless absolutely required. If you must drive, reduce your speed significantly.
      • Avoid operating engines of any kind. Ash can clog engines, damage parts, and stall vehicles.
      • Wear long-sleeved shirts and long pants.
      • Keep roofs free of ash in excess of 4 inches.
      • Limit outdoor activity. Remove outdoor clothing before entering a building.
      • Check to ensure that ash does not contaminate your water. If it does, use a different source, such as bottled water.
      • For more information about ash fall, check out the USGS Volcanic Ash website.

AFTER AN ERUPTION

    • Go to a designated public shelter or evacuation area if you have been told to evacuate or you feel it is unsafe to remain in your home. Text SHELTER + your ZIP code to 43362 (4FEMA) to find the nearest shelter in your area (example: shelter 98506)
    • Stay informed: Watch and/or listen for additional information. Listen to NOAA Weather Radio, watch TV, listen to the radio, or check the internet for official instructions and information.
    • Do not approach the eruption area.
    • Be prepared to stay indoors and avoid downwind areas.
    • Be aware of lahars and landslides. These hazards can occur long after the main eruption.

 

Stay tuned for: Volcano Hazards portal update, Volcano webpage updates, and more!

New Webpage Available: Rockhounding

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Washington has an extraordinary variety of rocks and fossils. Collectors have the opportunity to find beautiful agate, amethyst, garnet, jasper, opal, and even the occasional nugget of gold. Our state also has a plethora of fossils including crinoids, clams, trilobites, snails, corals, and at least one dinosaur. The state also has abundant petrified wood, which is the Washington State Gem, and has had over 40 Columbian Mammoth discoveries, which is the Washington State Fossil.

Check out our rockhounding page to find out:

Minerals and Fossils in Washington

rockhounding_storymap.jpgOur Mineral and Fossil Story Map compiles known locations of minerals and fossils such as petrified and opalized wood, fossil crabs, cephalopods, gastropods, trilobites, pelecypods, braciopods, leaf fossils, gemstones, geodes, zeolites, and chalcedony and opal. It is best viewed in full-screen mode.

The Rules

Be aware that this map may show locations where the minerals are amazing, but where rockhounding is not permissible. Determining land ownership and collection rules at that site is your first responsibility.

Before you set out, determine land ownership of your area of interest, learn the permissible collection activities and that owner’s rules governing where you can collect, what you can and cannot collect, and how it may legally be collected.

The consequences for collecting materials without permission are steep, as in most cases this would be considered trespassing and stealing.

ger_rockhounding_adit.pngSafety First

You’re responsible for your own safety. Steer clear of open mine tunnels or shafts—they can collapse, crushing you or trapping you inside. No mineral specimen is worth your life.

Where To Start

Our “Where Do I Start?” tab provides links to:

  • Museums like the Burke Museum in Seattle or Stonerose Interpretive Center in Eastern Washington
  • Local rock and gem clubs
  • Handbooks and publications on gold
  • Other rockhounding websites
  • And many others