Blackfoot Clearwater Stewardship Act This bill directs the Department of Agriculture (USDA) to complete a landscape assessment of the Seeley Lake Ranger District of the Lolo National Forest in Montana, designates areas in the forest for recreation and as wilderness, and otherwise revises provisions related to the forest. A collaboratively developed restoration project within the district may be carried out in accordance with certain hazardous fuel reduction projects. USDA shall, if a local collaborative group submits a proposal to improve motorized and nonmotorized recreational trail opportunities within the district, analyze the environmental effects of the proposal. It may also provide for the construction of any of the routes included in such proposal. The bill designates specified federal land in the forest as (1) the Otatsy Recreation Management Area, and (2) the Spread Mountain Recreation Area. The bill designates specified wilderness additions in the forest as wilderness areas and components of the National Wilderness Preservation System.