Shaping San Francisco Bicycle History Tour: Ecological History (North)

From SFBC:

This trip through San Francisco's lost sand dunes, ponds, creeks and coastline will focus on the city from downtown going north, covering the heart of the city, the waterfront and Yerba Buena cove, Telegraph Hill, Black Point, and Crissy Field in the Presidio... Sliding scale $15-50, benefitting Shaping San Francisco. For more info: 415.608.9035