By Eric M. Johnson ELLIOTT STATE FOREST, Ore., Aug 20 (Reuters) - Every time Dean Finnerty sees the locked neon-yellow gate and "No Trespassing" sign deep in Oregon's Elliott State Forest, he bristles at the growing movement to transfer federally owned land to U.S. states.

The 52-year-old conservationist and lifelong political conservative worries that cash-strapped states that acquire such land will ultimately be forced to sell to private companies only to extract oil, gas and timber.

He is one of many conservative outdoors enthusiasts to join liberal environmentalists in opposing such transfers.

They stand against business interests and conservative states' rights advocates who argue that handing the land to states will unleash its economic potential.

Finnerty likes to hunt bear and elk on public land in Oregon with his five sons. But their outings were curtailed two years ago when the state, which had acquired the land from the federal government, in turn sold some of it to logging companies.

"When the federal government owned these lands they were better equipped to keep and maintain them," said Finnerty, who keeps a handgun in his truck in case he encounters a mountain lion. "The idea that we could lose these federal public lands is not acceptable." Finnerty and his fellow sportsmen, many of them conservatives who instinctively oppose big government, are petitioning lawmakers, writing opinion columns and staging protests at state capitols. They fear losing access to prime hunting and fishing lands if states take control.

They have won backing from dozens of trade groups and companies, including fishing rod makers Orvis Corp and Sage and gun manufacturer Remington.

'ABSURD ... ABSENTEE OWNERSHIP' Their protest is at odds not just with anti-federalists such as the armed militiamen who seized control of the Malheur National Wildlife Refuge in Oregon earlier this year, but also many in the Republican Party mainstream.

Republicans last month officially embraced federal-to-state land transfers for the first time in their party platform, saying it is "absurd" that so much land is under Washington's "absentee ownership." The ideological standoff marks a new front in the "Sagebrush Rebellion," the decades-old fight over land-use in the U.S. West.

At stake is control of roughly 640 million acres of federally owned land, more than one-fourth of the U.S. land mass, most of which falls across a dozen Western states, according to the Congressional Research Service. https://www.fas.org/sgp/crs/misc/R42346.pdf For a graphic of federal land ownership across the United States, click here: http://tmsnrt.rs/2b8CKe1 Supporters say transfers could be lucrative. Oil and gas reserves on federal lands could generate $12.2 billion annually over the next decade, supporting more than 87,000 jobs, a 2013 University of Wyoming study estimated. http://goo.gl/7Mm8KY More than 30 bills pushing for federal land transfers were introduced in Western states in 2015, according to the Theodore Roosevelt Conservation Partnership, which opposes transfers. More than a dozen have been filed this year, said the Center for Western Priorities, another opponent.