Where are you going all depends on whom you contact. For instance; The BLM office for Montrose Colorado requires different types of permits for different types of prospecting, but if you go an hour North to Grand Junction they will tell you there are no permits because no prospecting is allowed.

Right now the Forestry Department and BLM are basically making up their own laws as they see fit, they could give a rats ass what you think or what even the State or Federal say, they make them up as they go.

Find the exact piece of land you are wanting to go to, contact the BLM or Forestry Department it is in and call them, and do yourself along with the rest of us a favor, ALWAYS BE POLITE.

Or you can just take your chances and go down with non-motorized equipment and unless you are in a National or State Park most will just ask you what you are up to and leave.