Tribe president Ben Shelly signed the legislation last week and said it needed to know if Navajo was beneficial for the group to obtain.

“We are in times unlike any other with federal budget cuts, reduced revenue and taxes,” Shelly said.

“We must consider investments that could help sustain critical programs that help our people.

“The due diligence investigation will help us learn all we need to know to make an informed decision about acquiring [the] mine.”

He highlighted that the Navajo Nation had not decided to buy the Navajo mine yet, as it was seeking more information about the entire operation of the complex.

“I also want to know how are we going to pay for the mine, if we decide we want to buy it,” Shelly said.

“And I want us to think far into the future and consider other technologies for clean coal.

“We need to look ahead and see how we can make use of our resources.”

The tribe began its due diligence process last December but the legislation signed April 3 will transition to review into the second phase.

The proposal for Navajo Nation to acquire the Navajo mine first came about after the Four Corners power plant and Navajo mine owners could not agree upon a coal price.

Shelly said the tribe was cognizant that about 800 of its people worked at the mine and generation facility and it wanted to protect those jobs as well.

“If acquiring Navajo mine can protect those existing jobs, it is my duty as president to ensure that we at least consider the proposal,” he said.

Should the Navajo Nation acquire the operation by June, the tribe said BHP Billiton would continue operating it through 2016.

Also, should the deal come to fruition, the group said it would buy all of the producer’s shares and merge the coal company with its still-to-be-determined Navajo company and would take over tangible and intangible property.

The tribe is targeting June 30 for its decision.

The Navajo mine is the sole provider of coal to the Four Corners plant near Farmington, New Mexico.

Arizona Public Service, which owns the facility, said about 6-8 million tons of coal per year would be needed to continue operations beyond 2016.

The Navajo mine supplied about 8.1Mt of coal to the plant in 2012, generating more than $40 million for the Navajo Nation.