According to this email from Murphy, there is another Two Wheel Locust / MCBC Fun Ride this weekend:
THIS course is RE-DONKLOUSLY FUN!!! More shade, less grind! See you there? 1/3 road, 1/3 rocks & 1/3 dirt.
Ride starts at 9:30 AM on Sunday (7/25/2010) at the Java Hut in
Marin FAIRFAX and again benefits the Marin County Bike Coalition. Bring $15 to support the MCBC.