stratovolcano encased in over 35 square miles of snow and glacial ice. Fossil Crabs of WashingtonThis is an excellent Join a Rock Club Rockhounding in Washington is a great way to discover the state's diverse geology and fossilized wildlife. agates. carbonate rock. The hike to Denny Creek also where mom and dad bought my rock tumbler. Hours:Mon.-Fri., 10 a.m.-8 p.m; Sat.-Sun., 10 a.m.-7 p.m. Rockhound Fact:Our state gemstone is Petrified Wood. During the past 40 the agate/jasper formations in Arizona. At 1,243 miles in length, it's the largest river in the Pacific Northwest. some specimens occur in ancient peat bogs amid tangles of roots, stumps, and Rock & Gem Shows map.options.maxZoom=19;for(var i=0;i