As spring approaches, rockslide dangers increase

Two rockslides in two days closed lanes closed lanes and backed up traffic along Highway 24 west of Manitou Springs.

“Some (of the) rocks (were) about three feet in diameter,” said Kenneth Quintana a highway maintenance supervisor for the Colorado Department of Transportation (C-DOT).

The road was clear Monday night, but the danger exists.

As it turns out, the rockslides are caused by a combination of water and time.

It’s one of the prettiest drives in the state – but danger lurks in Ute Pass and C-DOT is aware of the problem.

“Anytime you put highways through a mountain and you get these steep cliffs, that’s where you’re going to have problems,” said Quintana.

Falling rock signs are posted, but the reason for the danger for drivers goes back millions of years.

“There’s a very intensely fractured zone. These fractures are related to the presence of a geological fault,” said professor Christine Siddoway of Colorado College.

Siddoway said what is happening now that last week’s snow is melting: “That liquid water can change back to the ice form and as it does it acts just like a wedge,” Siddoway said.

Even large boulders are affected. Close examination reveals the fractures caused by the freezing and thawing cycle. After years of freeze and thaw cycles, pieces of the rock break off easily.

C-DOT will bring in crews to examine the area, but what they’ll do next depends on what they find.

“I’ve seen them use pry bars, I’ve seen them use air bags. There is one time they had to use explosives,” said Quintana.

Meanwhile drivers going through Ute Pass should be on the lookout.

Quintana said, “A lot of times some little rocks will come down before the big rocks come down.”

Quintana said February is a little early for rockslides.

He said most of the activity happens in March and April.