Occurs in western North America (California, Oregon, Washington, British Columbia). First description by Gray (1868, pp 369-370), accepted by Wallace (1975).
Scratchpads developed and conceived by (alphabetical):
Ed Baker,
Katherine Bouton
Alice Heaton
Dimitris Koureas,
Laurence Livermore,
Dave Roberts,
Simon Rycroft,
Ben Scott,
Vince Smith