DENVER (CBS4)– A controlled burn at the Rocky Mountain Arsenal Wildlife Refuge was sending a lot of smoke into the air northwest of the Denver metro area on Thursday afternoon.

The prescribed burn began at 10 a.m. and was scheduled to continue until 4 p.m. The U.S. Fish and Wildlife crews planned to burn a few hundred acres.

The black smoke was visible from downtown Denver.

The controlled burn as seen from the mousetrap at I-25 & I-70 (credit: CBS)

The controlled burn as seen from the mousetrap at I-25 & I-70 (credit: CBS)