Cache consists of a clear Rubbermaid container 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 = 915 ft
General Directions: To get to the trailhead drive to the Mardon Resort on SR 262, located at the west end of O’Sullivan Dam. At MP 14, follow the “Public Fishing” sign and descend eastward into scabland canyons below O’Sullivan Dam. At road’s end (1.6 miles from Mardon Resort) park at the boat launch area for Blythe Lake (N46.9585, W119.2943). A network of double-track as well as single-track trails lead to Upper Goose Lake and the geocache from this point.
Upper Goose Lake (Drumheller Channels)
Upper Goose Lake lies in the heart of Drumheller Channels, an awesome and chaotic network of channels, buttes, and rock basins carved out by great, cataclysmic Ice-Age floods. In 1986, the National Park Service formally recognized the stark beauty and significance of Drumheller Channels by designating them a National Natural Landmark. As described by J Harlen Bretz, the first geologist to piece together the evidence for the Ice-Age floods, “Drumheller is the most spectacular tract of butte-and basin scabland on the plateau. It is an almost unbelievable labyrinth of anastamosing channels, rock basins, and small abandoned cataracts”.
Some of the biggest and deepest potholes found anywhere, drilled into the basalt by swirling floodwaters, are present within Drumheller Channels. A number of these huge potholes lie along the route to the geocache.
Drumheller Channels connects the Quincy Basin, which is to north, with the Othello Basin on the south. Ice-Age floods inundated the Quincy Basin via Grand Coulee and off the Channeled Scabland via the Telford-Crab Creek scabland tract and Lind Coulee. When floodwaters encountered the Frenchman Hills, they were forced to divide. Some water flowed west over low points along Evergreen and Babcock ridges. The bulk of the floodwaters took the easiest path, which was straight south through Drumheller Channels.
Floodwaters naturally funneled through Drumheller Channels, carving out a well-defined, 12-mile-wide, 400-feet-deep swath across the east end of the Frenchman Hills. A series of straight, parallel grooves carved into the hard basalt bedrock reveal the incredible force behind the floods at this location.
The height of the floodwaters was about 150 feet different above and below Drumheller Channels. This significant difference in water level created tremendous erosion that scoured the complex network of channels, buttes, and basins here. However, unlike most other areas in the Channeled Scabland, no central channel or dominant cataract developed; instead, floodwaters passing through behaved more like a broad cascade—up to 12 miles wide! In all, Bretz reported 150 distinct channelways and over 180 rock basins in this region. Many of the low areas, including Upper Goose Lake, are filled by water seeping in through cracks in the basalt bedrock, which are connected with Potholes Reservoir to the north.
To experience more incredible features left behind by the Ice-Age floods try finding these other geocaches placed by geologist Bruce Bjornstad:
Staircase Rapids
Frenchman Coulee Rib
Rattlesnake Slope Erratics
Devils Canyon
Saddle Mountains Overlook (Earthcache)
Wallula Gap Overlook
Potholes Coulee
West Bar Overlook
Lake Sacajawea Flood Bar