Notes for Potential Hikers
The BDL route is about 212.5 miles and gains about 35,000 feet. To put this in perspective, the John Muir Trail is 210 miles in length and has a gain of around 46,000 feet. Given that the trail passes John Muir’s home, we think of it as a three-season JMT alternate, best hiked between September and May.
We walked the BDL March 6-16 of 2015. Including diversions to grocery stores, we walked about 220 miles on our trip. Subsequent to our completing the walk, various open-space agencies have acquired more land and constructed more trails. We updated the map in February of 2020 with a number of improvements made possible by these changes on the ground. We also rerouted a bit in Walnut Creek and in Fremont to move the walk off of some of the bigger streets. The CalTopo map now contain the new and improved route, shown as a red track. The map also includes our original 2015 walk shown as a green track.
In order to design the BDL James spent time over the course of a year studying park maps, satellite imagery, and Google street view. We took a scouting trip to investigate a couple of ambiguous areas. The big challenge was finding satisfactory links between parks, staying on various trail corridors and keeping off of roads as much as possible. Some of the links are not obvious from just glancing at a map, such as highway crossings enabled by unmapped pedestrian underpasses.
The route visits over 55 distinct parks including a National Historic Site, a State Park, many East Bay Regional Park District preserves, local city parks and recreation areas, land trust properties, non-motorized trail corridors, and water district properties. By piecing all of these together, road walking on a paved public road or on a sidewalk directly next to a street is reduced to a bit less than 12 miles; the longest piece is about 1.6 miles. Even though the route traverses Union City/Fremont, Livermore, and Walnut Creek, very little of it is on city streets because each of those towns has cross-town trail corridors. Some of the trails on the Loop are paved bike paths.
In many parks, there are numerous alternative ways to get from Point A to Point B; our choices were often arbitrary and there are many variations that could lengthen or shorten the route. Hike your own hike.
Roughly half of the loop follows the yet to be completed Bay Area Ridge Trail. Over time, trail access changes on the ground as the Ridge Trail Council and other agencies work to acquire and develop more parks and build new trails. We know of at least two areas where planning and/or trail construction is underway that will eliminate more of the road walking and make the park-to-park connections even better; we will update the route information when those connections are opened to the public.
The loop passes over three significant East Bay summits: Mission Peak, Rose Peak, and Mt. Diablo. There are many additional high points that provide fine vistas as well, sometimes with spectacular panoramic views over much of the Bay Area. From several high points, on clear days, the Sierra Nevada can be seen.
Habitats vary and include open grassland, oak savannah, oak woodland, riparian corridors, coniferous forest, redwood groves, chaparral, and 100 year old eucalyptus plantations. Some areas have active cattle grazing.
The BDL is a loop that can be started and completed at any point and walked in either direction. We use public transit whenever possible and since bus service from Palo Alto is fast and frequent to Fremont/Union City, we elected to start our walk there. The CalTopo map and route notes are written starting in Fremont and walking counter-clockwise.
Disclaimer: Do not rely on our exact tracks for your route; use skill and common sense. Use the stated distances as guidance; various sources of trail distances rarely agree.