The Cox Canyon Fire on the Southern Ute Indian Reservation east of Cortez was likely caused by a lightning strike last week, according to fire officials.

The blaze was announced about 3:30 p.m. Saturday via the Durango Interagency Fire Dispatch Facebook page, and by 6 p.m. it had grown to 10 acres. The Rocky Mountain Area Coordination Center said the fire was discovered Thursday at 7:25 p.m.

Smoke remained visible Sunday from U.S. Highway 550, in the area of Cox Canyon south of Bondad Hill.

Fire officials believe fire started from a lightning strike last week. In such cases, a lightning strike can cause a small fire that smolders for a few days before igniting into a larger fire.

The fire was burning in sagebrush, juniper and cedar trees.

Fire crews Sunday were mopping up and working toward containment.

“They’re just working to suppress the fire, contain it, and doing some mopping up of those hot spots,” said Lindsay Box, spokeswoman for Southern Ute Tribal Council Affairs.

Stage 1 fire restrictions remain enacted until conditions improve.

tbrown@durangoherald.com