The Harney Basin, located about 25 miles south of Burns, is a rockhounding destination in Harney County known for its diverse mineral deposits, including rare oolitic agate. Its rich material availability and convenient access via Highway 205 make it an excellent collecting site.

During the Pleistocene, the Harney Basin was part of an extensive network of interconnected lakes, including ancient Lake Malheur, which once drained into the Malheur River. Over time, geological uplift and volcanic activity destroyed this connection, leaving behind Harney and Malheur Lakes as remnants of a much larger water system. Today, the basin remains hydrologically closed, with water escaping only through evaporation, leading to mineral accumulation in the lakebeds.

Some areas of the basin are private land or part of the protected Malheur National Wildlife Refuge, so it’s essential to check land status before collecting. However, rockhounds can explore two Bureau of Land Management sites where collecting is permitted. They are listed below.

Be prepared – The high desert climate can be extreme, with hot summers and cold winters. Bring plenty of water, sun protection, and appropriate gear.

Harney Basin Rockhounding

This area is known for oolitic agate, a distinctive variety featuring small, spherical inclusions resembling fish eggs.

Oolitic agate forms when silica-rich water fills a cavity in a rock, depositing concentric layers of silica around tiny spherical particles called ooids. Over time, these ooids accumulate mineral layers, creating rounded “oolite.” This process typically occurs in shallow, supersaturated water environments where the ooids can roll and develop their characteristic coatings.

Besides oolitic agate, you can find jasper, petrified wood, and freshwater fossils.

The first collecting site is two miles west of Frenchglen Highway (OR-205) on South Harney Road. After a cattle guard, pass a dirty road on the right and stop at the second. The gravel piles on the right are a good place to start searching. There are a lot of materials on the surface. A geology pick can be helpful in uncovering buried specimens.

Many rocks here have been naturally tumbled by water. We found agate, jasper, and petrified wood in shades of gray, red, brown, black, and white shell fossils. A geology pick helps with extraction from the ground.

The second site is about 0.6 miles farther on the left. Park your car at a pullout and explore the gravel piles and hillside. The trail on the right leads up to oolitic agate deposits, though some can be found at the hill’s base.

There are several excellent rockhounding sites near Burns, including the obsidian deposits at Glass Butte and Mud Ridge. For those seeking plume agates, the Warm Springs Reservoir and North Beede Reservoir areas provide great opportunities.

Nearby, Diamond Craters presents an impressive volcanic field with diverse lava formations, perfect for geology enthusiasts. The small town of Field, 90 miles south, provides a quiet stopover, and the vast Alvord Desert offers a unique landscape for exploration. Geothermal wonders, Borax Lake Hot Springs and Mickey Hot Springs, are both worth a visit to enjoy volcanic activities in beautiful desert settings.

For a relaxing stay, Crystal Crane Hot Springs offers overnight accommodations and the chance to soak in mineral-rich waters.

From Burns,

Take Highway OR-78 and travel east to Highway 205
Turn right (south) to Highway 205 and follow it for about 24 miles to South Harney Road (milepost 24.9)
Turn right to South Harney Road and follow 1.6 miles to Site 1 at gravel mounds on the right.

For Site 2, continue 0.6 miles. Bear left to a pullout with gravel piles. The trail up leads to oolitic agate deposits.

GPS (Site 1): N 43°14.996' W 118°59.284' | 43.2499, -118.9881

GPS (Site 2): N 43°14.671' W 118°59.782' | 43.2445, -118.996