A series of mudslides caused by an intense storm forced the closure of a 35-kilometre stretch of B.C.'s Highway 99 in both directions north of Lillooet on Tuesday night.

The Ministry of Transportation says there are several slide sites with large debris deposits on the highway over an eight-kilometre segment of highway.

"The slides were the result of an intense storm cycle that went through the area earlier in the evening. This area is susceptible to debris flows under heavy rain conditions given the dry loose soil and lack of vegetation," says the website.

A ministry geotechnical engineer was flow in by helicopter to inspect the site, according to the website.

Lillooet mudslide

The slides were triggered by a severe storm around 11 p.m. PT Tuesday night. (Ministry of Transportation/Flickr)

On Wednesday night the route was reopened to a single lane of alternating traffic led by a pilot car. Drivers are advised to expect delays of up to 20 minutes.

Near miss for one driver

There are no reports of any injuries, but several vehicles were stuck between the slides. Crews were able to get everybody out safely overnight, but had to leave the trapped vehicles along the highway.

Amber Wright was driving from Cache Creek to Lillooet last night when she drove over a small slide. Then she was stopped by a wall of mud and rocks about five meters high.

"It was a huge slide. It was literally just mud and rock and it would have gone right into the lake. Because you couldn't see anything, because of the rain and hail, you literally would have just slammed right into the slide. So it was pretty scary."

Mud and debris also crashed into some cabins around Pavilion Lake, according to Patricia Heintzman, the chair of the Squamish-Lillooet Regional District.

"An anecdotal assessment is that there was enough mud and debris that came down that was about 10 feet high in some of the homes," said Heintzman. 

Updates to the closure will be posted on the Drive BC website