Ecological History Bike Tour

From SFBC:

This trip through San Francisco's lost sand dunes, ponds, creeks and coastline will focus on the city south of downtown and SOMA, traversing the Mission, Mission Bay, Potrero Hill, Bayview, and the southeast coastline, including several new public parks. Bring a snack and water, and reserve your spot: 415-608-9035, sliding scale $15-50, benefiting Shaping San Francisco