A massive rock slide blocking the Potash road since early Tuesday will be blasted to break up boulders and loosen a huge slab suspended precariously above the highway.

Sam Taylor, state highway commissioner, said Utah Department of Transportation officials met Wednesday to negotiate an action plan with the U.S. Corps of Engineers and Denver & Rio Grande Railroad Co.Officials said the railroad tracks and U-279 about 12 miles from the junction with U.S. 191 were covered by falling rock that broke away from sheer cliff walls between 4 and 6 a.m. Tuesday. Some boulders bounded across the road onto a sandbar of the Colorado River, which parallels the road.

"They're going to take those rocks and blow them up and take them out of there, and then go up on the cliffside and blast those," Taylor said.

"Three or four are big as a house."

Taylor said the agencies have to come to agreement on where to dispose of the debris. Blasting the rock to pieces and hauling it away will be a tremendous expense, he said.

"But we have to do that, because of the impact on the river. It puts mud in the river. These new wetlands rules are really stringent and this whole thing falls under wetlands mitigation," Taylor said.

Officials at Moab Salt Inc., which operates a plant about 15 miles downriver, said the rock slide was reported to the Grand County Sheriff's Office about 6:40 a.m. by Rick Klein, production supervisor.

"I've seen a couple of falls on this road, but this is the biggest," said Ruth Christensen, a personnel secretary at the plant.

Moab Salt's 53 employees had to walk across the debris and were shuttled to work throughout the day while UDOT workers cleared a swath large enough for cars to pass, said Eric York, general manager.

"We're directing personal vehicles and company vehicles into the plant, but we've requested no commercial trucks come in. We've asked people who ship with us not to come through," York said Wednesday.

"There's one large piece of rock hanging above the roadway that will inevitably fall, probably when they start moving the fallen rock," he said. "It kind of tilts toward the river, and rocks are trickling down and it's not stable, and it is really a big rock."

York said falling rock is a common occurrence along the road, which was cut into the sandstone cliffs lining the river in the 1950s.

"Everybody out here has got stories about having to dodge rocks, so it's not an unusual thing. Rocks are falling on the road all the time. It's unusual to go a month without at least seeing rocks in the road," he said.