Brooklyn Bridge Loop Professional Review and Guide
"Located 8 miles south of Helena on the divide between Jefferson and Lewis and Clark counties. A marathon ride with a remote feel and the gamut of singletrack conditions--arduous climbs, sweet downhills, boulder gardens, logs to bunny hop, bog crossings, sidehills, and route-finding riddles. A fair chance of seeing deer, elk, black bear, and other wildlife.
Portions of this ride traverse private holdings, some of which may be posted against trespass. Please heed all posted property boundaries. Also, the USDA Forest Service may regard some long-abandoned roads as part of a proposed "vegetation manipulation" project. Future access is uncertain."