Oregon State Police say the landslide occurred on the south side of I-84 Wednesday evening and sent two thousand cubic yards of rock and debris onto the highway.
This has forced the closure of both east and westbound lanes. The closure will remain in place at least through the weekend.
The closure affects nearly fifty miles along the interstate.
ODOT is recommending drivers use alternate routes by using U.S. 26 or I-205, but expect long delays.