New Mexico
There are only about 100 miles of groomed trails in New Mexico but there are plenty of riding areas that are accessed by forest service roads and other old mining roads.
And, despite the lack of an extensive groomed trail system, New Mexico sees a good number of sledders each winter who come from places like Oklahoma and Texas for the backcountry riding.
New Mexico's major mountain range is the Rocky Mountains and it's along the spine and sides of those mountains much of the riding is found.
The major riding areas in the state are (from north to south): Chama, Red River (where the groomed trails are), Angel Fire, Mt. Taylor, San Pedro Mountains, Jemez Mountains and Cloudcroft.
A good source of information on snowmobiling in northern New Mexico can be found at www.fs.fed.us/r3/carson. Once there, go to the "recreational activities" section and click on the snowmobile info. You can also try www.fs.fed.us/r3/sfe.