One of the joys of owning land in Maine is that Maine’s Landowner Liability Law offers owners some strong protection. Basically, if someone uses your land for outdoor recreation you assume no responsibility or liability for injuries–whether or not you give permission.
There’s a great brochure developed by the Maine Department of Conservation and the Department of Inland Fisheries and Wildlife on this topic. You can find a copy (along with some other great information) under the landowner relations program web site.
There are, of course, exceptions to everything… and the standard caveats (check with your insurance company, attorney, etc.). One caution to landowners is that you avoid creating clearly dangerous conditions that could be considered “mailicious” failure to guard or warn (or correct) a highly dangerous situation.
A caution to “land users” is that this law does not imply that you have the right to use other people’s land. Access to private land is a privilige, not a right, and you should aways seek permission.