Have an interest in the paleoenvironments and geological features of the areas you visit? If so there’s a good chance your going to enjoy the Stonerose Interpretive Center located in the foothills immediately west of the Kettle River Range in the town of Republic WA. Stonerose is the name of a fossil site, a place where impressions of plants, insects, and fish that lived 50 million years ago (Eocene Epoch) can be found in shale.
The mountainous area around Republic WA, just 12 miles west of the Kettle Crest Trail, was once a vast lake. Due to the volcanic activity many layers of powdery ash sediment built up on the lakebed. These layers of the old lake bottom can be seen today as layers of fine-grained tuffaceous shale, volcanic ash hardened into sedimentary rock. The layers of shale split apart like pages in a book revealing fossils and information about the ancient lake and its surrounding vegetation. Within these layers, the insects and fish that drifted to the lake bottom, and the leaves and twigs that floated downstream or blew into the lake can now be seen as fossils.
By the time the Stonerose fossils were laid down, the great age of the dinosaurs was long past. The giant reptiles had been extinct for fifteen million years. The Pacific Northwest was very different from the region we know today. The Cascade Mountains were not there to block the flow of warm, moist air from the Pacific, so the climate was warmer and wetter than today's. The ancestors of our familiar temperate-forest trees intermingled with broadleaved trees, which are now native to the southeastern states and to plants that today grow only in the Far East.
Some of the plants/animals found at Stonerose are now extinct; fossils are all that remain. The ecologically successful plants have left many descendants that are still recognizable all around the world.
Unlike many fossil sites, Stonerose is a hands-on experience. The public is welcome to visit Stonerose and search for fossils in the Eocene fossil beds. At the time of your visit, the Stonerose staff will explain the rules for digging and how to find fossils. After showing all your finds to the staff for identification, you may keep three fossils per day.
My thanks to Catherine Brown, ex-director of Stonerose Interpretive Center
Stonerose Interpretive Center