MINNEAPOLIS – Citizens in northeastern Minnesota plan to file a petition Tuesday objecting to the state’s plans to auction off more metallic minerals exploration leases, saying the potential for new prospecting and mining could have a significant impact on the environment.

A copy of the petition provided to The Associated Press on Monday asks for the Department of Natural Resources to prepare an environmental assessment worksheet before awarding the leases, saying they could affect trout streams and other sensitive natural resources, drinking water wells, popular recreational trails and property values. More than 140 people have signed it.

The DNR announced plans to auction the mineral rights to 64,000 acres earlier this month amid growing interest in the large untapped reserves of copper, nickel and precious metals under northern Minnesota. The affected lands are in St. Louis County, in and near the city of Hoyt Lakes; in Lake County about 2 miles west of Tettegouche State Park; and in a rural area of eastern Aitkin County.