Eastern Washington (Saddle Mountain, Beverly)
Petrified wood including Ginkgo wood (outside the state park), agate, and jasper in the Columbia Basin. Hot and dry in summer.
92 mapped spots across 30 counties. Washington has good public access for agate, petrified wood, quartz crystals, geodes, and fossils. Saddle Mountain, Walker Valley, Hansen Creek, and the Stonerose fossil site at Republic are the names most rockhounds start with.
Map showing 92 rockhounding spots in Washington
Counts reflect how many spots in this list mention each mineral.
Notable areas: Walker Valley geodes, Hansen Creek quartz and amethyst, Saddle Mountain petrified wood, and Stonerose Eocene fossils are common Washington targets.
Eastern Washington is largely covered by Miocene Columbia River Basalts, which buried and silicified forests now collected as Saddle Mountain and Beverly petrified wood. The Cascades expose altered volcanics with quartz pockets and geodes, including Hansen Creek and Walker Valley. In the northeast, the Republic lake beds at Stonerose produce Eocene plant and insect fossils.
Petrified wood including Ginkgo wood (outside the state park), agate, and jasper in the Columbia Basin. Hot and dry in summer.
Walker Valley geodes near Mount Vernon, Hansen Creek quartz and amethyst crystals near Snoqualmie. Wet and brushy — gloves and boots required.
Eocene plant and insect fossils at the Stonerose Interpretive Center. Pay an entry fee, get a permit, dig the lakebed shale, and keep up to three specimens per visit.
Beach agates, jasper, and fossil wood along the Pacific shoreline. Olympic National Park is closed to collecting; nearby state and tribal beaches have separate rules.
East side: April–October. West side: drier May–September. Stonerose: open May 1 through October 31, weather dependent.
Cascade locations need rain gear and waterproof boots much of the year. East-side desert spots need sun protection and water. Stonerose loans hammers but bring safety glasses and a hand lens.
Washington designated petrified wood as its state gem in 1975. Near Vantage, the Ginkgo Petrified Forest preserves trees buried by basalt flows about 15 million years ago.
Day-trip range. Each section lists the closest mapped rockhounding spots within about 150 miles of the city — most are inside a 2 to 3 hour drive.
6 closest spots to Seattle, WA.
6 closest spots to Spokane, WA.
Geology rarely respects state borders. These states share mapped rockhounding country with Washington — useful when Washington is the start, not the whole trip. Each card links to the closest county across the line.
County pages are linked once we have at least 3 mapped spots for a focused guide with coordinates, mineral notes, and nearby spots.
Sorted by county. Tap coordinates to open in Google Maps, or open RockHoundR for the full map view with land overlays and weather.