Obsidian is found across the western United States, concentrated in states with volcanic history: Oregon, California, Wyoming, Utah, Idaho, Arizona, and New Mexico. These states sit along geologically active zones where silica-rich lava once cooled into the glassy black rock that rockhounds and collectors prize today. If you’re looking for specific sites you can actually visit and collect from, several are on public land and open to the public.
Why Obsidian Is a Western Rock
Obsidian forms when silica-rich volcanic lava cools in a way that prevents crystals from developing, producing solid glass instead of grainy rock. Contrary to what many people assume, research published in Nature Communications shows obsidian actually requires relatively slow cooling to form properly, on the order of days to years. This slow process allows gas bubbles trapped in the lava to be reabsorbed, leaving behind the smooth, glassy texture obsidian is known for.
Because it requires volcanic activity involving the right type of lava, obsidian deposits are almost entirely limited to the geologically young volcanic regions of the American West. You won’t find natural obsidian in the eastern half of the country, though ancient trade networks carried it there thousands of years ago.
Oregon: The Richest Collecting Ground
Oregon has more accessible obsidian sites than any other state, thanks to its Cascade Range volcanism and high desert geology.
Glass Buttes is the most famous collecting destination in the country. Located in central Oregon’s high desert, this complex contains at least seven distinct geochemical groups of obsidian, meaning the glass varies in composition from one area to another. Collectors find black, mahogany, rainbow, fire, and silver sheen varieties all within the same general area. Glass Buttes sits on Bureau of Land Management land, so collecting for personal use is allowed without a permit.
Newberry Volcanic Monument is home to the Big Obsidian Flow, the youngest lava flow in Oregon at roughly 1,300 years old. This massive flow covers just over one square mile and is a striking landscape of chunky black glass. It’s managed by the Deschutes National Forest and is an interpretive site, meaning you can hike through it and observe, but collecting is not permitted here.
California: Davis Creek and the Modoc Plateau
Northeastern California’s Modoc National Forest hosts one of the best-known obsidian collecting areas in the country: Davis Creek. The U.S. Forest Service designates four specific collection zones here, each producing different varieties of obsidian. The sites are Middle Fork Davis Creek, Needles, Pink Lady, and Rainbow. As the names suggest, you can find everything from standard black obsidian to rainbow and pink-hued varieties depending on which area you visit.
Collection at Davis Creek requires a free use permit from the Warner Mountain Ranger District, and not all four areas are open at all times. It’s worth checking with the ranger station before making the trip. The obsidian here tends to be high quality, with clean fractures and vivid color, which is why the site has drawn collectors for decades.
Wyoming: Obsidian Cliff in Yellowstone
Obsidian Cliff, located about six miles north of Norris Geyser Basin along Highway 89 in Yellowstone National Park, is one of the most historically significant obsidian deposits in North America. Indigenous tribes from across the Midwest and Great Plains used this site as a major source of toolmaking stone for thousands of years. Obsidian from this cliff has been identified at archaeological sites more than a thousand miles away.
Because it sits within a national park, collecting is strictly prohibited. But the cliff face, a wall of black volcanic glass visible from the road, is worth seeing if you’re passing through Yellowstone.
Utah: Black Rock Desert
Utah’s Black Rock Desert in Millard County offers one of the easiest obsidian collecting experiences in the country. According to the Utah Geological Survey, you can walk in any direction from the parking area and find obsidian lying on the ground. Most pieces are black and range from half an inch to six inches across, though some reddish-brown and snowflake obsidian turns up as well.
To reach the site, you drive south from Delta on Highway 257 for about 43 miles, then follow a dirt road east for roughly six miles to a spot called Black Spring. The area is remote, so bring water and check road conditions before heading out, especially after rain.
Other Notable States
Idaho has several productive obsidian sources, particularly in the eastern part of the state near the Snake River Plain. The volcanic geology that feeds Yellowstone extends into Idaho, producing scattered obsidian deposits.
Arizona is known for Apache tears, small rounded nodules of obsidian found weathering out of volcanic rock. The area around Superior, Arizona has historically been a popular spot, though many of the most accessible sites are now on private or restricted land.
New Mexico has obsidian sources tied to its Rio Grande Rift volcanism. The Jemez Mountains and areas near Grants have produced obsidian used by Paleoindian and Pueblo cultures for thousands of years.
Rules for Collecting on Public Land
Most obsidian collecting in the U.S. happens on Bureau of Land Management or National Forest land, and the rules vary by agency and location.
- BLM land: In Oregon and Washington, you can collect up to 250 pounds per day for personal, non-commercial use without a permit or fee. Anything over that weight, or any commercial collection, requires a BLM permit.
- National Forests: Rules differ by forest. Some sites like Davis Creek require a free use permit. Others restrict collection entirely, especially within volcanic monuments or interpretive sites.
- National Parks: Collecting any rocks, including obsidian, is always prohibited in national parks and national monuments.
Before visiting any site, check with the local land management office. Regulations can change seasonally, and some areas close temporarily for wildlife protection or road conditions. Bringing a GPS or detailed directions is also smart, since many obsidian sites are on unmarked dirt roads in remote desert terrain.