The Border Lands Conservation Act seeks to improve border security and management on federal lands adjacent to the U.S. southern and northern borders. It directs the Secretaries of Interior and Agriculture to install and maintain navigable roads on these lands, in consultation with the Department of Homeland Security (DHS), to deter illegal crossings and enhance operational control. These roads would also increase DHS access for security purposes and require cooperative agreements for technology installation.

The bill significantly amends the Wilderness Act, granting DHS broad authority to conduct various activities within wilderness areas for border security, including using motor vehicles, aircraft, and deploying tactical infrastructure. It also prohibits federal land management agencies from impeding DHS search and rescue or unlawful entry prevention operations within 100 miles of the borders, and mandates interagency cooperative agreements with DHS for national security efforts.

Furthermore, the Act establishes a Border Fuels Management Initiative to reduce hazardous fuels and address invasive species on covered federal land, prioritizing areas with new roads. It also mandates an inventory of unauthorized roads and trails created by illegal crossings, with a provision for their maintenance and use by DHS if they cause significant environmental degradation.

The legislation requires several reports to Congress detailing environmental degradation, wildland fires, visitor safety impacts, and effects on ranching caused by illegal immigration on various federal lands, including National Parks and Wildlife Refuges. Finally, it prohibits the use of federal funds to house undocumented aliens on these lands, with an exception for detention facilities, and includes a savings clause to protect existing legal land uses and tribal sovereignty.