Cache consists of an ammo box with logbook, pencil, pencil sharpener, standard cover sheet, and flyers of the Ice-Age Floods Institute (IAFI). The IAFI is a non-profit organization devoted to informing and educating the public about these unique geologic events that shaped the Pacific Northwest as recently as 13,000 years ago. See www.iceagefloodsinstitute.org, for more information.
Cache Elevation = 1655 ft
General Directions: At Washtucna go north on SR 261 8 miles. Turn right (east) onto unpaved Sutton Rd. Continue two miles to Snyder Rd and turn right (south). Go one mile to end of road and beginning of trail. From the trailhead it’s a flat 0.4 miles to the lip of the upper rapids, near the site of an old dump. This eyesore is soon forgotten as you walk east and are rewarded with expansive views from the top of the rapids for another 0.4 miles.
WARNING: Seasonally, lots of rattlesnakes have been observed in this area.
Staircase Rapids is a now-dry series of cascades once filled with hundreds of feet of water during the cataclysmic Ice-Age floods. Staircase Rapids descend like stair steps between Rattlesnake Flat to the north and Washtucna Coulee to the south. The subdued topography in the Rattlesnake Flats area sharply contrasts with the deeply eroded scabland of Staircase Rapids itself.
The rapids were contained on either side by Palouse uplands eroded by the floods. A number of residual, streamlined and scarped hills are found here. The head of Staircase Rapids, which is 3.5 miles wide, is interrupted by several sizable loess islands. Steeper scarped slopes around streamlined Palouse islands, planed off by the floods, record the maximum height of the floodwaters. Bretz used these scarped slopes to discover the floods dropped an amazing 300 feet in only 6 miles between Rattlesnake Flat and Washtucna Coulee! Knowing the gradient of the floods enabled Vic Baker later to calculate the speed of the floodwaters at an incredible 100 ft/sec (~70 mph) across this steeply sloping surface.
Staircase Rapids also was affected by tectonic fracturing, making the rapids vulnerable to erosion. A segment of the head of the rapids and several notches cut into the head of the rapids on the west side are all parallel and thus related to the same tectonic-fracture system. A deep rock basin lies at the base of the upper rapids, eroded by spillover from the floods.
A trail crosses rich farmland to an overlook across the uppermost rapids onto the scablands below. The trail is located on private land and made open to the public through an agreement with the Washington Department of Fish and Wildlife. No motor vehicles are allowed. Please respect the land and remember public access on these private lands is a privilege – not a right.
To experience more incredible features left behind by the Ice-Age floods try finding these other geocaches placed by geologist Bruce Bjornstad:
Upper Goose Lake
Frenchman Coulee Rib
Rattlesnake Slope Erratics
Saddle Mountains Overlook (Earthcache)
Wallula Gap Overlook
West Bar Overlook
Lake Sacajawea Flood Bar