t2 Leave at 8:30am at the Lake Merced Boat House area in San Francisco.
Route A (Vanilla): 29 miles with 2,870 feet of climbing (includes Golden Gate Park, Twin Peaks, and San Bruno Mountain).
Route B: 38 miles (add a round trip to the North end of the Golden Gate Bridge).
Route C: add the Marin Headlands loop to Route B.