With time running out on the Biden administration, a push is underway to have President Joe Biden designate a national monument on nearly 140,000 acres in North Dakota next to Theodore Roosevelt National Park.

Those behind the effort cite the region's long ties to Indigenous cultures and threats posed by "[C]orporate oil and gas development and its associated infrastructure." Proposed to be situated on 11 non-motorized backcountry designated areas of the Dakota Prairie Grasslands in the Badlands of the Little Missouri River Basin of western North Dakota, the envisioned Maah Daah Hey National Monument would link the north and south units of Theodore Roosevelt National Park.

It also would be threaded by the existing 144-mile-long Mah Daah Hey Trail, which touches "[M]ajestic plateaus, jagged peaks and valleys, large expanses of rolling prairie, and rivers ... to offer the adventurous outdoors enthusiast a taste of pure, unadulterated wilderness." Hikers, backpackers, and trail runners make up about 70 percent of trail usage, according to the Mah Daah Hey Trail Association, while mountain bikers account for about 24 percent, and equestrain about 6 percent.

The Mandan and Hidatsa tribes have deep connections with this landscape. "In the Mandan language, the phrase 'Maah Daah Hey' means “grandfather, long-lasting,'" those behind the effort say. "It is used to describe things or an area that have been or will be around for a long time and is deserving of respect."

Traditionally, tribal members would come from the Heart and Knife River confluences to the Little Missouri region to trap eagles, hunt bison, and gather medicinal plants.

In 1851, during negotiations at Fort Laramie in Wyoming Territory, the tribes were given the northern terrain of the Little Missouri River drainage.

The boundaries of the Mandan, Hidatsa, and Sahnish (Arikara) territory were set-aside in the 1851 Fort Laramie Treaty: Commencing at the mouth of the Heart River; thence up the Missouri to the mouth of the Yellowstone River; thence up the Yellowstone to the mouth of Powder River, thence in a southeasterly direction to the headwaters of the Little Missouri River, thence along the Black Hills to the headwaters of the Heart River; thence down the Heart River to the place of the beginning.

Part of that territory today is the Little Missouri Grassland District of the Dakota Prairie National Grasslands. In 1993 there was an effort by the two tribes, along with The Wilderness Society, National Wildlife Federation, National Parks and Conservation Association, American Rivers and others to have an official wilderness designation placed on much of the landscape, but it was unsuccessful.

"The landscape has long been inhabited by native people. The area in the proposed monument is under massive threat from development," proponents of monument designation say. "Oil and gas wells and their associated infrastructure continue to invade some of the wildest places in North Dakota. The proposed national monument would bring permanent conservation of 139,729 acres of the North Dakota Badlands along and near the Maah Daah Hey Trail."

The proposal didn't indicate which federal lands management agency the monument should be placed under, though the Dakota Prairie National Grasslands is managed by the U.S. Forest Service.