eastbound on Interstate 82
- Plucking (Wikipedia)
Plucking, also referred to as quarrying, is a glacial phenomenon that is responsible for the weathering and erosion of pieces of bedrock, especially large “joint blocks”. This occurs in a type of glacier called a “valley glacier”. As a glacier moves down a valley, friction causes the basal ice of the glacier to melt and infiltrate joints (cracks) in the bedrock. The freezing and thawing action of the ice enlarges, widens, or causes further cracks in the bedrock as it changes volume across the ice/water phase transition (a form of hydraulic wedging), gradually loosening the rock between the joints. This produces large pieces of rock called joint blocks. Eventually these joint blocks come loose and become trapped in the glacier.
Washington Trails Association
- Umtanum Ridge Crest (wta.org)
Get a workout on this steep hike along the Vista Trail from Umtanum Creek to the ridge above the canyon. In spring, it is filled with wildflowers and birds, with chances of seeing rattlesnakes and bighorn sheep. In the fall, there are amazing views from Ellensburg to the Wenas to Yakima and more with fall foliage.
westbound on Interstate 82
- Umtanum Ridge (Wikipedia)
Umtanum Ridge is a long anticline mountain ridge in Yakima County and Kittitas County in the U.S. state of Washington. It runs for approximately 55 miles east-southeast from the Cascade Range, through the Yakima Training Center to the edge of the Columbia River at Priest Rapids Dam and Hanford Reach. The eastern end of Umtanum Ridge enters Hanford Reach National Monument and the Hanford Site. Umtanum Ridge is paralleled on the north by Manastash Ridge and on the south by Yakima Ridge. The Yakima River cuts through the ridge at the Umtanum Ridge Water Gap.