About 425,000 square miles of "land that nobody wanted" is administered by the federal Bureau of Land Management, and in almost 300 places in the West, the BLM had a convenient parcel to use for a landfill.
Typically, the BLM leased the land to the county for a nominal fee, and had some requirements. The landfill had to be fenced, burning was forbidden, and trash had to be covered every day. If the site filled, then the county leased another parcel from the BLM. That doesn't happen any more. The Recreation and Public Purposes Act of 1988 terminated the authority of the Secretary of the Interior to lease public lands for solid-waste disposal. In 1992, the BLM issued regulations implementing the act (HCN, 12/27/93).
What of current landfills on BLM land? The BLM plans to sell them to the counties. BLM doesn't want the landfills because of potential Superfund liability, and the transfer requires the county to assume all "potential liability associated with the use of these sites for solid waste disposal."
As for the future, BLM policy is to allow local governments to acquire public lands for use as landfills. But getting the land can be a complex process, subject to political vagaries. Most counties building new landfills look everywhere else before turning to the BLM, whereas the BLM used to be the first option, and generally an easy one.
The change in BLM policy added another level of complexity to trash in the West, just when the EPA was providing plenty of complication, all on its own.