* Rio Tinto gains control of copper-rich acreage in

Arizona

* Resolution to spend $500 million on new drilling

* Project has support of President Donald Trump

* Supreme Court has not stepped in to block

By Ernest Scheyder

March 16 (Reuters) - Rio Tinto said on Monday it

has gained control of acreage in Arizona needed to build the

Resolution Copper mine, a project slated to become one of the

largest U.S. sources of the critical mineral but one that Native

Americans have opposed for more than 20 years.

The move marks what is likely the end of a long-running and

complex legal fight in which the religious rights of the San

Carlos Apache people were pitted against rising demand for

copper for the energy transition and Washington's efforts to

wean itself off foreign supplies.

Anglo-Australian miner Rio Tinto gave the U.S. Forest

Service 5,400 acres (8.4 square miles) of land in Arizona in

exchange for access to 2,400 acres that contain more than 40

billion pounds (18.1 million metric tons) of copper, a crucial

building block for electric vehicles, cables, and electronic

devices.

The land swap came after a U.S. appeals court last week

again rejected requests to block it and the U.S. Supreme Court

did not take emergency measures to step in.

Rio said it would now launch a $500 million drilling

campaign to explore the deposit, a necessary step before the

company can forecast when copper production could begin.

Representatives for the San Carlos Apache and their

attorneys were not immediately available to comment. The tribe

has long said Washington had no right to the land that it

swapped with Rio, going so far as to file a property lien in

2021.

"This responsible mining project fulfills President Trump's

vision of American mineral independence," U.S. Agriculture

Secretary Brooke Rollins said on Monday. The Agriculture

Department controls the U.S. Forest Service.

COURTS REPEATEDLY REBUFFED APACHE CALLS TO BLOCK MINE

The San Carlos Apache and their allies fought for years to

stop the land swap, arranged by Congress in 2014, because the

mine will eventually swallow a site known as Oak Flat, or

Chi'chil Biłdagoteel in the Apache language, where many worship

their deities.

Multiple courts, including the Supreme Court, have

repeatedly rejected their requests to block Resolution.

Trump publicly voiced support for the project last August.

In a post on his Truth Social platform at the time, he said

those who opposed the mine "are Anti-American, and representing

other copper competitive Countries."

Rio and minority partner BHP Group ( BHP ) have spent more

than $2 billion on the project without producing any copper.

"As demand for copper continues to grow, projects like

Resolution can play an important role in strengthening domestic

supply chains," said Katie Jackson, head of Rio's copper

business.

BHP, which controls 45% of the project to Rio's 55%, said

that Resolution "is positioned to be an engine for economic

growth in the U.S., creating thousands of high-value, local jobs

and billions in economic activity nationwide."