By Dave Tucker and Kitty King
December 5, 201o
Northwest Geology Field Trips subscriber Kitty King of Blaine alerted me to a glacial erratic in Blaine, which recently emerged when brush were cleared along H Street Road. The 2-meter-high rounded stone is one of those wonderful conglomerate boulders from the euphonious Jackass Mountain Formation in southern British Columbia. These distinctive rocks are found in a number of places in Whatcom County. Others that have been profiled on this website are Donovan Rock in Bellingham and the Malloy Village erratics in Ferndale. The Donovan Rock webpage discusses the geology and significance of the Jackass Mountain conglomerate erratics. Among other things, these distinctive boulders demonstrate that the ice that blanketed the Whatcom lowlands originated in the interior of British Columbia, and flowed down the Fraser River valley rather than flowing directly southward out of the BC Coast Mountains.
To see the erratic, go 0.5 miles east up the H St hill from the intersection with WA 543 (the truck route to the border crossing). The boulder is in a yard on the north side just beyond Parkview Place. Parking is a problem: best bet my be to turn around at the top of the hill using Allan Street, then come back down and park on the grassy roadside just west of Lincoln Lane. The erratic is on private property, but it can be admired from the roadside. You might want to take along binocs to see the clasts if you are averse to walking up to it.