BILLINGS, Mont. — Dozens of American Indian communities Tuesday joined an initiative to return millions of acres of reservation land to the control of tribal governments as U.S. officials warned the $1.9 billion program will run out of money before the task is completed.

A total of 63 reservations in 16 states in the West and Midwest were added to the Interior Department’s “Land Buyback Program,” bringing the total number involved to 105.

The land purchases resulted from legal settlement with American Indians led by Elouise Cobell of Montana, who said the U.S. mismanaged trust money held by the government on behalf of hundreds of thousands of Indians.

The program has paid more than $742 million to landowners since 2013. Looking ahead to its 2022 expiration date, Interior officials indicated the remaining money will be gone and they’ll need to go back to Congress to work out a solution.

The 1.5 million acres restored to tribes to date represent the “low-hanging fruit” of relatively inexpensive land, said John Dossett, general counsel for the National Congress of American Indians. Land that’s more valuable — for example, because it has timber, oil or other natural resources — could cost more and take longer to acquire, he said.

“Tribes were hoping for this $1.9 billion obviously, and it’s a very significant down-payment, but it’s not going to be enough,” Dossett said.

The goal is to consolidate land that has split or “fractionated” ownership, freeing it up for economic development or other uses by tribal governments.

An 1887 law, the Dawes Act, split tribal lands into individual allotments that were inherited by multiple heirs with each passing generation.

As a result, parcels of land on some reservations are owned by dozens, hundreds or even thousands of individual Indians. That can make property all but impossible to sell or develop.

There are nearly 3 million fractional land interests owned by 245,000 people spread over 150 reservations that are eligible for the program. Many of the purchases to date comprised large parcels on Western reservations with a large land base. That includes at least 200,000 acres each on the Crow, Fort Belknap and Fort Peck reservations of Montana and the Pine Ridge and Cheyenne River reservations of South Dakota.

Interior Deputy Secretary Michael Connor said in a Tuesday statement that time limits and the money available from the Cobell settlement “do not provide enough to consolidate all fractional interests across Indian Country.”

Connor has been told by Interior Secretary Sally Jewell to craft options by early July for extending the life of the program.

That could include bumping back the expiration date, adding more money or some combination of the two, said Interior spokeswoman Treci Johnson.

Tribes added to “Land Buyback Program:”

— Absentee Shawnee Tribe of Indians, Oklahoma

— Apache Tribe, Oklahoma

— Blue Lake Rancheria, California

— Cherokee Nation, Oklahoma

— Cheyenne &Arapaho Tribes, Oklahoma

— Citizen Potawatomi Nation, Oklahoma

— Colorado River Indian Tribe of the Colorado River Indian Reservation, Arizona and California

— Comanche Nation, Oklahoma

— Confederated Tribes of the Warm Springs Reservation, Oregon

— Eastern Shawnee Tribe, Oklahoma

— Forest County Potawatomi Community, Wisconsin

— Fort Independence Indian Community of Paiute Indians of the Fort Independence Reservation, California

— Habematolel Pomo of Upper Lake, California

— Ho-Chunk Nation of Wisconsin

— Hoopa Valley Tribe, California

— Hopi Tribe, Arizona

— Kalispel Indian Community of the Kalispel Reservation, Washington

— Keweenaw Bay Indian Community, Michigan

— Kickapoo Tribe of Indians of the Kickapoo Reservation, Kansas

— Kiowa Indian Tribe, Oklahoma

— Kootenai Tribe, Idaho

— Lac Courte Oreilles Band of Lake Superior Chippewa Indians, Wisconsin

— Lac du Flambeau Band of Lake Superior Chippewa Indians of the Lac du Flambeau Reservation, Wisconsin

— Minnesota Chippewa – Bois Forte Band (Nett Lake), Minnesota

— Minnesota Chippewa – Grand Portage Band, Minnesota

— Minnesota Chippewa – Leech Lake Band, Minnesota

— Minnesota Chippewa – Mille Lacs Band, Minnesota

— Minnesota Chippewa – White Earth Band, Minnesota

— Morongo Band of Mission Indians, California

— Muckleshoot Indian Tribe, Washington

— Nisqually Indian Tribe, Washington

— Omaha Tribe, Nebraska

— Otoe-Missouria Tribe of Indians, Oklahoma

— Pala Band of Luiseno Mission Indians of the Pala Reservation, California

— Pawnee Nation, Oklahoma

— Pechanga Band of Luiseno Mission Indians of the Pechanga Reservation, California

— Pueblo of Laguna, New Mexico

— Quileute Tribe of the Quileute Reservation, Washington

— Red Cliff Band of Lake Superior Chippewa Indians, Wisconsin

— Red Lake Band of Chippewa Indians, Minnesota

— Rincon Band of Luiseno Mission Indians of the Rincon Reservation, California

— Sac &Fox Nation of Missouri in Kansas and Nebraska

— Sac &Fox Nation, Oklahoma

— Saginaw Chippewa Indian Tribe, Michigan

— Santee Sioux Nation, Nebraska

— Skokomish Indian Tribe, Washington

— Spirit Lake Tribe, North Dakota

— Spokane Tribe of the Spokane Reservation, Washington

— Stockbridge Munsee Community, Wisconsin

— Suquamish Indian Tribe of the Port Madison Reservation, Washington

— Sycuan Band of the Kumeyaay Nation, California

— The Chickasaw Nation, Oklahoma

— The Choctaw Nation of Oklahoma, Oklahoma

— The Muscogee (Creek) Nation, Oklahoma

— The Seminole Nation, Oklahoma

— Tohono O’odham Nation, Arizona

— Tulalip Tribes, Washington

— Upper Sioux Community, Minnesota

— Ute Indian Tribe of the Uintah &Ouray Reservation, Utah

— Ute Mountain Tribe of the Ute Mountain Reservation, Colorado, New Mexico and Utah

— Walker River Paiute Tribe of the Walker River Reservation, Nevada

— Yurok Tribe of the Yurok Reservation, California

— Zuni Tribe of the Zuni Reservation, New Mexico