There is more to the BLM than the management of sage grouse and range fires. Consider FLPMA, where Congress directs the BLM to provide multiple uses for the benefit of the American people on public lands:
In the Federal Land Policy and Management Act of 1976 as amended in 2001, Congress directs the Bureau of Land Management "To establish public land policy; to establish guidelines for its administration; to provide for the management, protection, development, and enhancement of the public lands; and for other purposes." http://www.blm.gov/flpma/FLPMA.pdf
Section 102 Declaration of Policy
(a) The Congress declares that it is the policy of the United States that–
(7) Goals and objectives be established by law as guidelines for public land use planning and that management be on the basis of multiple use and sustained yield unless otherwise specified by law.
Section 103 Definitions
(a) The Congress declares that it is the policy of the United States that–
(c) The term “multiple use” means the management of the public lands and their various resource values so that they are utilized in the combination that will best meet the present and future needs of the American people; making the most judicious use of the land for some or all of these resources or related services over areas large enough to provide sufficient latitude for periodic adjustments in use to conform to changing needs and conditions; the use of some land for less than all of the resources; a combination of balanced and diverse resource uses that take into account the long-term needs of future generations for renewable resources and non renewable resources. . .
From Gary Pearson: "Public land is to be used for public purposes and the subject proposed transmission line is the classic definition of a 'public purpose' endeavor."