Two hundred and twenty-six-million pounds of rock from the Ferguson Slide covered about 750 feet of the highway in 2006.
CC Myers of Myers and Sons Construction says he expects crews to begin removing rocks from the area starting late this summer.
"We gotta take all the material off of the mountain that's loose," he says. "We gotta clean that mountain, then put cables down, tying steel steel mats down, so that when people are working down below, somebody can't get hurt."
Caltrans says about 70,000 cubic yards of rock must be removed.
When the rock is gone, Myers says crews will build a long tunnel called a rock shed.
"You build a wall on each side," he says. "And then you put a roof on the top on a slope so if any of the mountain comes down again it'll go right over the roof and down. It'll never close the highway again."
The slide blocked direct access from Mariposa to Yosemite for two years. A one-lane bridge with a stop light was built around the slide in 2008 to allow access to the park. That bridge will be removed when the rock shed is finished.