BLANDING, Utah (Reuters) - Activists seeking to directly challenge federal control of swathes of territory in the U.S. West plan to embark on an all-terrain vehicle ride on Saturday across protected land in Utah that is home to Native American artifacts and where such journeys are banned.

The ride into Recapture Canyon, which comes amid heightened political tensions, is aimed to protest against indecision by federal land managers on whether to reopen canyon trails to recreational vehicle use after more than seven years of study.

The dispute is the latest squabble between conservative state's rights advocates in Utah and across the West, who want to take back millions of acres of public land over which federal agencies have authority. In Utah, more than 60 percent of all public land is under federal control.

"After seven years, it's become apparent that they are not earnest in doing what they said they were going to do," San Juan County Commissioner Phil Lyman, who is organizing the ride, told Reuters, adding he was aware he could be arrested or cited for encroaching closed areas in violation of federal rules.

The ride comes in the wake of last month's armed standoff between supporters of Nevada rancher Cliven Bundy and federal land managers who unsuccessfully sought to seize his cattle by force over his longstanding refusal to pay grazing fees because he doesn't recognize federal authority.

It was not immediately clear how many people might join Lyman's effort, which will include trail rides that are near, but not in, the closed area of the canyon for any participants who do not wish to directly violate the rules.

Bundy has called for his army of supporters, at one point nearly 1,000 strong, to participate in the Recapture Canyon ride as a show of solidarity with Utah.

The Bureau of Land Management said it regretted the ride was going forward despite an entreaty by the agency to cancel it, adding it would seek "appropriate penalties" against anyone who violated the law.

"Recapture Canyon is public land belonging to all Americans and contains ancient cultural sites and artifacts that are at serious risk of being destroyed or damaged," Bureau of Land Management Utah State Director Juan Palma said in a statement.

The canyon in the Four Corners region of Utah is home to the ruins of ancient dwellings and other cultural resources of Ancestral Puebloans. The BLM closed the area in 2007 after an illegally constructed trail was found and some artifact sites were damaged.

San Juan County officials sought a right of way through the canyon more than seven years ago, including a 14.3-mile network of motorized vehicle trails at the canyon's north end, and proposed giving up a claim to the southern end in hopes of gaining BLM approval. The agency has not yet decided the issue.

Utah Governor Gary Herbert, a Republican, said in a statement his office was working closely with the BLM to resolve the dispute, but urged "everyone to uphold the law and not do anything that could disrupt public safety."

(Editing by Cynthia Johnston)