After moving back to the San Francisco Bay Area in 1997 I discovered the Bay Area Ridge Trail, which took about a calendar year to weekend hike the 250 mile loop in sections. Over the years I continued to hike all the rest of the trail systems linking to the ridge trail, increasing my annual miles from 250 a year to 300, then 350, surpassing a bit more every year until I peaked out in 2011.with 380 miles.

In 2006 I started the hobby of digitizing them with GIS software. The large image shows the scope of the work, and I believe this is the most comprehensive trails layer publicly available of the nine Bay Area counties. The links offer some regional details, and you can also download a .kmz file of the hikes and fly around in Google Earth and check them out.  SF Bay Area Trails KMZ

East Bay 1

East Bay 2




South Bay 1

South Bay 2

About the Routes: Heads-up digitized in 2006-2007 from various regional park maps and commercial trail maps, using 2 meter aerial photography, USGS quad sheets, Tele-Atlas and GDT road data, and field verified the existence and connectivity of the trails by walking them. Individual arcs are not named by trail. The name field represents a single day hike with an arbitrary name. The label field is a concatenation of name and miles. Mileage figure is based on arc length. In the original geodatabase the arcs are classified by 1 for loops and traverses, and 2 for in-out trails, multiplied accordingly, and summarized and dissolved in the final KMZ file.