The state will groom some popular trails (lincoln woods..) but unfortunately they get post holed by hikers and snow shoe-ers because I guess the ski tracks looks easier to walk in or something.

Most of the fire roads get groomed real well by sleds. The skiing is usually great esp if you have metal edges. You have to stay vigilant as those guys do like to go fast and are often drinking.

Mountain bike trails and any kind of flat or undulating open forests are great for xc skis.

What part of the state are you in?