There's gold - and much more - in the hills of Malheur County, and that could prove to heat up an already-hot debate over what to do with the vast area of eastern Oregon desert.

According to a new report by the Oregon Department of Geology and Mineral Industries, Malheur and several other counties in southern and eastern Oregon have significant mining potential for metallic and industrial minerals.

That's big news for opponents of the proposed Owyhee Canyonlands National Monument, which would protect more than 2.5 million acres of federal land in the county, making it off-limits to mining of any kind.

"Even though we have determined that there's high potential for gold, silver other kinds of resources out there, there are so many other things that determine whether a mine can make a go of it," department spokeswoman Ali Hansen told Oregon Public Broadcasting last week.

The report comes only months after Oregon Senators Jeff Merkley and Ron Wyden introduced a bill in Congress that would withdraw more than 2 million acres of federal land in the county from mining and drilling.

Their proposal would be a blow to mining interests - which have already been popping up around the county for years - but it's written to protect local ranches and farms, where some of the most vocal critics against the national monument can be found.

Andrew Bentz and Andy Gaudielle, of Calico Resources USA, stand atop an estimated 425,000 ounces of gold valued at more than $1,500 an ounce at today's prices in the bowels of Grassy Mountain in southeastern Oregon's high desert south of Vale in 2012.

According to the Southeastern Oregon Mineral Withdrawal and Economic Preservation and Development Act, the proposal is meant to "preserve the traditional uses and values of the communities" and "to protect against the harmful effects mining and oil and gas extraction could have on the unique and important resources of the region, particularly water quality, grazing, and other economic development opportunities."

Several prominent farming and cattle groups - like the Oregon Farm Bureau and Oregon Cattlemen's Association - are publically opposed to the national monument, supporting the vocal "no monument' movement spearheaded by the Owhyee Basin Stewardship Coalition, a group of ranchers with grazing allotments in the proposed 2.5 million acres.

Supporters of the monument have assured that existing farms and ranches will still be able to operate, and that grazing allotments on the land won't go away, but mistrust of those promises (and of the federal government in general) runs high in Malheur County.

In May, county residents voted overwhelmingly against the designation, with an enormous 90 percent of voters opposed. While extremely one-sided, the advisory vote carries no weight and consisted of less than 20 percent of the county's population.

There's no indication whether or how the new report could sway the debate. Mining potential for gold and yellowcake uranium in eastern Oregon is no secret, and while Sens. Wyden and Merkley's bill aims to protect farmers and ranchers from the effects of mining, there's no evidence that opponents to the monument will suddenly change their tune.

The Owyhee Canyonlands National Monument could still be approved by President Obama or by an act of Congress, protecting a huge swath of desert wilderness, but it would likely do nothing to ease tensions over federal land ownership in eastern Oregon.

--Jamie Hale | jhale@oregonian.com | @HaleJamesB