GEORGETOWN, Colo. - A 25-mile stretch of Colorado's main east-west highway was shut down Tuesday so crews tethered to a mountainside by ropes could pry loose unstable boulders threatening to tumble onto traffic 300 feet below.Crews removed dozens of boulders - a few 5 to 10 feet wide - from the mountainside above Interstate 70 before reopening the highway shortly before 5 p.m.Rocks posing an immediate threat were removed, although the Colorado Department of Transportation planned to return over the next couple of weeks to replace a net that catches rocks and to anchor boulders that employees believe could eventually become problems. Another interstate closure is possible."You have mountain goats up on the hill, and they get to kicking those rocks and you have them come down," said Marty Marrone, who works at MountainBuzz Cafe & Pizzeria in picturesque Georgetown, across the highway from where the work was taking place."Plus, you have the winter spring thaw that loosens them up. I keep an eye out for them," Marrone said.Falling boulders killed two people on I-70 near Georgetown in 1999.The state transportation department has spent about $9 million to date on preventing unplanned rockslides in the area, agency spokeswoman Stacey Stegman said.Engineers have draped huge steel mesh curtains to rein in boulders on some slopes, and built retaining walls to keep falling rocks off I-70. On rare occasions, they close the highway so crews can dislodge unstable rocks without threatening traffic.On Tuesday, about a dozen crew members in hard hats were working on the hillside. Some broke up rocks with high-pressure devices and then pried them loose with poles 6 to 8 feet long.Boulders as large as a picnic table tumbled down the slope behind the steel mesh, clacking against other boulders and bringing a shower of smaller rocks with them.Residents of five homes were asked to evacuate as a precaution, and cargo containers were lined up beside the highway to keep any boulders from bouncing across the road and down into Georgetown. None of the falling rocks came near homes or vehicles.The atmosphere was almost festive in Georgetown, a community with deep roots in Colorado's mining and narrow-gauge railroad history. Residents gathered in small groups on street corners to gaze up at the work about a quarter- to a half-mile away."I wanted to watch the rocks fall down," Georgetown resident Tom Elliott said.Elliott said a rock hit a Volkswagen he was riding in several years ago, bouncing on the trunk lid and over the top but missing the windshield."I've been aware of these rocks for years, so I try to avoid them," he said.Rockslides are a natural hazard of mountain travel, said Stegman, the department spokeswoman. The state Transportation Department has a rating system to monitor potential rock falls at more than 750 sites across Colorado, including 18 around Georgetown alone."We're never going to be able to prevent all of those," she said. "What we do by way of mitigation is try to reduce the probability of a major slide, or try to slow the rocks so they don't come into contact with vehicles."An average of 30,000 vehicles travel I-70 near Georgetown every 24 hours, and closing it cuts off traffic between Denver and some of Colorado's biggest ski areas. Traffic stops of about 20 minutes were planned Wednesday for cleanup work.The Loveland Ski Area offered free breakfast to skiers and snowboarders who came up early to beat the closure."The parking lot is not even half full," said Randal Nichols, 31, a snowboarder from Springville, Calif., who made it to Loveland from the Denver area before the closure. "There was actually longer lines for breakfast than the lifts."Loveland marketing assistant Carly Knutson said skier numbers were down slightly Tuesday but still better than expected.Vail Resorts offered lodging packages for customers who wanted to ski during the highway closures. Keystone Ski Resort extended its operating hours Tuesday and Wednesday.
Associated Press writers Catherine Tsai and Sheila V Kumar contributed to this report from Denver.