This large caterpillar was found on dirt right next to the concrete garage apron. The branched hairs are very distinctive, indicating probably a Hemileucinae. The one dorsal stripe is a pale but distinctive aqua. We have seen Coloradia pandora at this location, about 6400', but so far I cannot locate an image of an immature. Another possibility Is Hemileuca eglanterina as we have seen it at slightly higher elevations, but this cat does not seem to match any of the H. eglanterina cats in the BugGuide collection. Right now the cat is burrowing into sandy soil in the bottom of an aquarium. Any help with its ID is greatly appreciated.

I just checked out C. pandora cats in Lepidoptera of the Pacific Northwest: Caterpillars and Adults. Their cat has much shorter barbed hairs and the coloration and pattern seem quite different.