The canyon, a popular recreation area outside Moab, was named after William Grandstaff, a black cowboy who ran cattle in the area in the 1870s.
Mary McGann, a Grand County Council member who fought for the change, praised the board's decision.
"I am very pleased with what the board decided to do," she said. "It was the right thing."
In 2016, the Bureau of Land Management changed out the Negro Bill Trailhead sign along the Colorado River corridor on state Route 128 north of Moab to signal its official support for a name change.