Private property!! This is a new trail prompted by a controversial fence erected by Marin rocker James Hetfield of Metallica. He allowed access up until some clown vandalized the property, then it was fenced and patrolled. The 680 was a huge endeavor that was expensive, and there are opinions as to whether or not it was worth it. Singletrack is rare in these parts, and it links to many other routes. Thus making it worth it, in my book...
Respect all private land, please.
Access 680 Trail from: (1) the end of Manuel T. Freitas Pkwy (this is the long way). It dead ends and there is parking at either side of the street and access via the Mission Pass Bike Path which pops over to Fawn Dr. which has access there but limited parking. There is a dirt road turn at the crest of the path called Terra Linda Ridge fire road. I like this way as there are a few challenging ups and downs along the way. (2) The main, easy access (short way) route and its associated parking is off of Lucas Valley Road and Mt Muir Ct. Take the other end of Terra Linda Ridge fire road up. Look for a little dirt parking area and a wood rail gate (pass through on left) with some signs on it. This turn is easy to mistake as it is right next to a residential iron entry gate.
Once at the top your possibilities are endless. Catch the Bay Area Ridge Trail
(BART) and head up to Lucas Valley Preserve and Big Rock Trail
. Or, head down toward Tamarancho to Repack
and the White Hill Open Space. Either way you'll have a blast!