The Navajo Nation and federal officials have signed a historic land-swap agreement that Navajo President Peterson Zah said gives many families "land they can call their own."

The agreement affects more than 150,000 acres of Navajo and Bureau of Land Management land in San Juan and McKinley counties.The swap will consolidate scattered BLM and Navajo holdings, giving the agency and the tribe more solid blocks of land in an area that is currently a checkerboard of ownership.

BLM State Director Larry Woodard said the agreement he signed Monday was "an effort to try and resolve a century of confusion."

The agreement, which will take at least two years to implement, will not change the way the parcels of land are being used.

But for many families, it will mean they are finally living on Navajo-owned land rather than being considered illegal occupants of federal land, officials said.

"It's a historic day for the people who live in the Eastern Navajo Agency, particularly," said Zah, who signed the agreement during a brief ceremony at the Museum of Indian Arts and Culture.

"They were living on land they did not have legal title to. Now they have a land they can call their own," the president said.

The residents will be able to run electric and water lines to their homes for the first time, Zah said. The land probably will be put in trust for the families, he said.

About 70 families are affected by the agreement, officials said.

BLM Director Cy Jamison, who attended the ceremony, said the agreement was the product of tough negotiating.

"These are the kinds of things we like to see taking place" because it indicates that problems are being worked out at the local level, Jamison added.

The agreement was also signed by Bureau of Indian Affairs Navajo Area Director Walt Mills.

The land exchange had been under discussion for years, but finally materialized when federal and tribal officials ate together after Zah's inauguration in January and sketched out the plan on a paper napkin, said Ron Fellows, area manager of BLM's Farmington Resource Area.

The napkin was displayed in a frame at the ceremony.