i dont know about national forest , but i know where i work (state park/wildlife management area) the dogs have to leashed AT ALL TIMES....even if they are 19 miles away from the campsites...during the hunts, there is no camping allowed and the dogs are allowed off the leash, but this only happens a few days out of the year......they dont want harrassment of the animals of any kind, dogs tend to get lost chasing critters they arent suppose to be chasing.....there are many factors......this is just a couple, i would recommend going to the website of the place you want to go and ask them, they know better than anyone else.......