We have photographed these kadydids for several years at several locations in Olympic National Park: Sunrise Ridge trail, Obstruction Point Road, Blue Mountain and the Elwha Trail, west of Hurricane Hill.
All the specimens we’ve seen and photographed are femalesnote the long ovipositor. It turns out that some kadydid populations are parthenogenetic, so this population may also be parthenogenetic.
The genus is probably Steiroxys, and the species may be undescribed. (See Bugguide.net page)
It’s also possible that these are Sterioxys trilineata. Dan L. Johnson, University of Lethbridge, has photographed S. trilineata (See three-lined shieldback). A 1907 publication of the United States National Museum describes S. trilineata and includes this figure. (See the Google Book search result for this publication.