Fire crews have fully transitioned to mop-up work Monday after containment of the 159-acre blaze reached 40% and firefighters completed hose lays, the Oregon Department of Forestry reported in a Monday press release.

According to ODF, lightning from a Thursday thunderstorm ignited the Cottonwood Creek Fire, but it was not reported until Friday afternoon.

ODF’s press release noted that dozers, wildland engines, helicopters and air tankers were successful in stopping forward growth of the fire by late Friday evening.

Fire officials, ODF said, have been concerned about burning snags and “rollers” for the last several days as they worked to strengthen fire lines and keep the fire within the original footprint. “Rollers” are burning chunks of logs or other material that can ignite unburned fuels as they roll down steep terrain, according to ODF.

ODF said that the fire is being managed by a Type 3 organization from ODF’s Central Oregon District.

Ten wildland engines, five hand crews, three water tenders and additional overhead are assigned to the fire. Local aircraft are available as need to support firefighting activities, according to ODF’s press release.