SFBC: San Francisco’s Presidio: A Fresh Look

"The transformation of the Presidio is accelerating, and changes to the
forests, natural areas, architecture, and bike paths are worth a close
up look. This tour of the Presidio's backroads is led by a Natural
Areas program volunteer and SFBC member. Easy ride on pavement - be
prepared to ascend twice to the Presidio's ridge line.

Rain
cancels rides."