I thought I would start compiling a list of trails in the UP region in one place to help make it easier for people to research and find some of the epic trails in the area. This will be a work in progress and I'll keep updating this original post. If you have some links or maps to offer please post them up!

Marquette, South Trails, maintained by the Noquemenon Trail Network
http://noquetrails.org/pages/thetrails/maps/SouthTrailsMapOrtho.pdf

Marquette, North Trails, the best map I could find and it highlights specifically the course from the 12 Hours of Potluck race, the other trails are also visible


Marquette Mountain Ski Area trails


Grand Island National Recreation Area


Porcupine Mountains State Park mountain bike trails
http://www.michigandnr.com/Publications/PDFS/RecreationCamping/Porkies_mtbiketrailmap.pdf

Copper Harbor trail system... BIG map

Maasto Hiihto trails


Swedetown trails


Bruno's Run
http://www.fs.fed.us/r9/forests/hiawatha/recreation/biking/brunos_run/map.pdf

http://www.keweenawtrails.com/mountain.html

Has most of the trails in the Keweenaw area.

The Adventure Trails map is now available!
http://www.adventureminetours.com/Adventure_Trails.pdf

that underground section must be insane.

thanks for sharing.

If by insane you mean one of the easiest sections of trail that we have then yes. Most people think its the hard section when it's actually pretty easy but lots of fun.