San Juan County Sheriff Rick Eldredge says from 40 to 50 people drove about a mile down Recapture Canyon near Blanding and then turned around.
BLM Utah State Director Juan Palma, in a statement, says the riders may have damaged artifacts and dwellings that are up to 2,000 years old, and the agency will pursue "all available redress through the legal system" to hold them accountable.
Commissioner Phil Lyman, the protest's organizer, says it was designed to show that the federal agency isn't the "supreme authority" and local residents have a right to have their opinions heard.
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