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 will inspecting the area this morning by helicopter, according to the website.
"There is no local detour available. The alternate route to Lillooet is via Highway 12 to Lytton and then Highway 1 to Cache Creek. Traffic control persons are on site to inform the public about the closure and potential alternate routes."
There are no reports of any injuries, but several vehicles were reportedly stuck between the slides.
Updates to the closure will be posted on the Drive BC website