I was out there a couple years ago, but I came in from the residential neighborhood to the west. FYI, that bridge that crosses the track has a "do not enter" sign and multiple "no parking" signs are around that neighborhood. woops. The southern most section is the old railbed, and should be easy to find from the northern section of the rainbed. The other section of the trail seemed very horse friendly and erroded. Personally, the railbed was OK to ride, but nothing to write home about. The horse trail was a horse trail. Starting out further south across Blue Ridge Blvd. and staying east of the river is a much more enjoyable ride. You can park safely at the baseball field just east of Blue Ridge Blvd and Holmes, or at any of the strip mall places off holmes once it gets dark. I don't know if I'd leave my car unattended too many other places at BURP during the night if no one's around.
"A hundred travel books isn't worth one real trip"