Not sure who keeps the trails in Copper Harbor in shape but I'd guess its the members of the local IMBA club there. In Duluth, where we do most of our riding, the COGGS group (Cyclists of Gitchee Gummi Shores) maintains our trails. Its mostly volunteer labor that gets together to fix a section but they do have some full time summer trail builders that build new trails, repair old sections, etc... Right now they have Aaron Rogers from Rock Solid Trails in Copper Harbor (he built a lot of the Copper Harbor trails) building sections of the new Duluth Traverse, which is a trail that will run the length of Duluth along the ridge line connecting all the different riding areas together. Rode by a new section of it last night, when done it'll be a 26 mile long trail.