Derek, don't forget the white pelicans and cormorants - and especially Ed's favorites, the otters! Ribka, when people use (some/all?) Federal land for commercial purposes (like hunting and fishing guides, rafting operators, etc.), they are supposed to get the applicable Federal Use Permit and they can and do get fined if they are caught without it. These permits are issued for specific areas, have their own rules, and if they conduct operations in multiple areas, they have to have multiple permits. For instance, I know someone who has a permit for the Grand Ronde and Rufus Woods. Unlike leasing grazing rights, it does not give them the exclusive use of that resource and if it did, I am sure the price would be much higher. I am sure that if a guide service could pay $2000/year to have exclusive rights to fish on X river or X lake and keep all anglers off it (but not other recreationists like canoe, kayaks, etc), most would jump at the chance and depending on the particular body of water, there may be an outright bidding war.