BILLINGS, Mont. (AP) — Federal officials on Thursday doubled the number of American Indian communities involved in a $1.9 billion government effort to return lands on reservations to tribal ownership.

Twenty-one Indian communities in 12 states will join the land buyback program by 2017, said Deputy Secretary of the Interior Mike Connor. That brings the number of locations in the program to 42.

"Right now the program is accelerating," Connor said. "Our outreach efforts and coordination with tribal leaders and government is becoming more effective."

The buyback program was a central piece of a $3.4 billion settlement in 2009 of a class-action lawsuit filed by Elouise Cobell of Browning who died in 2011. The lawsuit claimed Interior Department officials mismanaged trust money held by the government for hundreds of thousands of Indian landowners.

The 1887 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.

The buyback program aims to buy land with "fractionated" interests and consolidate ownership of the parcels under tribal governments.

"We have some plots of land that have 500 owners on one, little 20-acre tract," said Grant Stafne, a member of the executive board for the Assiniboine and Sioux Tribes of the Fort Peck Reservation in northeast Montana. "We would have control over our land instead of individual Indians. It would make it easier to lease land."

In the buyback's first year, $225 million was paid to individual Native Americans for restoring the equivalent of 375,000 acres to tribal governments, Connor said.

During testimony before Congress earlier this year, tribal leaders including Stafne criticized the program for its slow pace. They also said they were being shut out of decisions on what land to buy.

Connor said Thursday the government is making adjustments as the program grows, but Stafne said problems persist. One thing his tribes want is to put the buyback money into their own interest-bearing account.

"We could buy land on that interest alone," he said.

Fort Belknap Tribal President Mark Azure said Thursday that a cooperative agreement with federal officials had eased some of his earlier concerns about the program.

But Azure said Fort Belknap leaders still have too little say over which parcels are chosen.

He added some landowners remain reluctant to participate in the federal program, but if the tribe had more control over it those landowners might be willing to sell.

"That's where we as tribes hopefully provide answers to all of their questions," he said. "They would lean more toward tribal government in bringing in answers that are going to make sense."

Roughly 245,000 owners of fractionated land on 150 reservations are eligible to participate in the program.