18,000 to 15,000 years ago, massive floods reached this location starting from catastrophic ice dam collapses near Missoula, flowing southwest across northern Idaho and eastern Washington and eventually surging out of the constrictive Columbia Gorge. Here the floods flowed past this hill (a Boring Lava Field volcano). The summit of the hill, now known as Prune Hill, was just above the flood. In the eddy of the hill downstream, rock and gravel was deposited where the waters slowed. The deposit, known as the Mill Plain Pendant Bar, now appears as a ridge along the north side of the Columbia River reaching from Prune Hill to downtown Vancouver. We have lived along this ridge and enjoyed the views from it since 2003. Similarly, the Alameda Ridge Pendant Bar, was formed by the floods flowing past Rocky Butte (another Boring Lava Field volcano) and depositing sediment to the west.
The cache is a pill-bottle sized container Parking is nearby.
Congratulations to rodwellerduo and trailtrekn for a shared FTF.