Just a short drive east of Cheney, Washington, lies Fish Lake Regional Park, a beautiful 76-acre space offering more than just typical park amenities. This area, easily accessible with parking, play areas, hiking trails, and a swimming beach, tells a dramatic story of a landscape shaped by immense Ice Age floods. You’ll find a paved parking lot at the northeast edge of the park, right by the Fish Lake trailhead. From here, you can hop onto the Columbia Plateau State Park Trail and start your adventure!
What makes Fish Lake truly unique is its geology. It’s a double plunge pool, a fascinating feature created by powerful, swirling currents during these ancient mega-floods. These paired, counter-rotating currents scoured out the lake basins, and during periods of low water, you can even spot a partial rock ridge, or rock blade, that divides the two pools. An even larger basalt rock blade separates Fish Lake from the nearby Minnie Creek rock channel and a wide, swampy area it drains into.
The significance of Fish Lake isn’t lost on those who study these incredible floods. The local chapter of the Ice Age Floods Institute (IAFI), now the Cheney-Spokane Chapter, has been exploring and educating about this area since 2004. Early field trips introduced members to the flood-formed features around Cheney and the Palouse region, with Fish Lake being a key example. Remarkably, even the pioneers of Ice Age Floods research, Joseph Pardee and J Harlen Bretz, visited the Fish Lake area over a century ago, recognizing the powerful forces at play. For those interested in learning more, a video explaining the formation of these scour lakes is available on the IAFI website under the Cheney-Spokane chapter.
Geologically, Fish Lake sits on a fascinating junction. It was carved into a chemically weathered contact zone between very old metamorphic rock, dating back a staggering 1.47 billion years, and much younger basalt flows from the Columbia River Basalt Group, around 16 million years old. The lake’s eastward drainage into the Minnie Rock channel further illustrates the powerful erosive forces of the floods. Evidence even suggests the floodwaters in this area reached incredible heights, exceeding 2600 feet, as seen in a small scour lake near Prosser Hill.
So, next time you’re looking for a park with natural beauty and a captivating history, consider visiting Fish Lake Regional Park. It’s a place where you can relax and play while standing in a landscape sculpted by one of Earth’s most dramatic events.
Condensed from an article by Dr. Linda McCollum, President, Cheney-Spokane Chapter