Historic avalanche conditions persisted Thursday in the mountains of Colorado, shutting down portions of a vital highway that traverses the state and prompting a rare warning for drivers to avoid traveling through the region that’s home to many ski resorts.

After another round of heavy snow, an avalanche struck early Thursday near Vail Pass along Interstate 70, catching a tow truck at its outer edge.

The driver was not hurt and another tow truck had to pull his truck from the slide, which left 6 feet (2 meters) of snow on the road, transportation officials said.

[SEE IT: Massive Colorado Avalanche Engulfs Highway]

A few hours later another avalanche ruptured a natural gas line to the east near Copper Mountain ski resort. Gas was turned off to the two buildings served by the line — a wastewater treatment plant and a gas station.

Crews have not been able to repair the break yet because of the ongoing avalanche danger, Xcel Energy spokeswoman Michelle Aguayo said.

The cleanup work from the Vail Pass slide and later from avalanches intentionally triggered by road crews to avoid more problems shut down portions of I-70 in the mountains.

Closures could be lengthy and people were urged to avoid traveling along I-70 in the mountains, Colorado Department of Transportation spokeswoman Tracy Trulove said.

The avalanche danger in the central mountains was rated as extreme, the highest rating.

The Colorado Avalanche Information Center said high snowfall for March combined with strong winds have created some of the most dangerous avalanche conditions in years.

An avalanche on Sunday stunned drivers along the interstate, sweeping vehicles off the road but not causing any injuries.

All the new snow has proved to be too much of a good thing for some ski resorts.

Arapahoe Basin ski resort closed due in part to the extreme avalanche danger. In addition, an access road was closed by the avalanche danger. Other resorts were open, including Copper Mountain but with some lifts closed.

One intentionally triggered avalanche near the town of Empire reached Interstate 70 for the first time since 1957.

Snow from another intentional avalanche near the Eisenhower Tunnel covered all four lanes of the highway and left snow and other debris up to 15 feet (5 meters) deep over a 300-foot (91-meter) stretch of the road, the center said.

(AP)