(a) You should file an application (Form 4120-7) with BLM for a permit to do this. A permit will allow you to construct, maintain, and use any fence, building, corral, reservoir, well or other improvement needed for grazing under the grazing permit; and
(b) You must comply with Alaska state law in the construction and maintenance of fences, but any fence must be constructed to permit ingress and egress of miners, mineral prospectors, and other persons entitled to enter the area for lawful purposes.