Bishop’s Cap embodies the highway engineering genius of Samuel Lancaster. The base of a basalt outcropping was undercut as little as possible to accommodate traffic. Locals call this altered formation “mushroom rock” due to its similarity to a stem connecting to a mushroom cap.
The same motif is repeated around the bend. More highway architecture is visible in the form of dry masonry walls and stone guardrails.
by Judy Jewell and W. C. McRae from Moon Oregon, 8th Edition, © Elizabeth & Mark Morris and Avalon Travel