The scene at the Upper Applegate Fire from a Facebook post Saturday morning by the Oregon Department of Forestry.

Wildland firefighters are making “tremendous progress” on the Upper Applegate Fire south of Ruch, and a Type 1 helicopter is being demobilized as fire bosses say they feel comfortable with downsizing the air-support fleet.

With overnight work by fire crews, the fire has only slightly expanded to 966 acres from Friday’s 937 acres, but mop-up has increased to 20%, according to a Facebook post Saturday morning from the Oregon Department of Forestry. 

The cause of the fire has been determined to be mowing in dry grass, ODF reported Thursday. No additional information into the fire investigation was available late Saturday morning.

The fire is now 100% directly lined, meaning there are no unburned interior pockets along the perimeter that could easily allow the fire to burn over a line, the Saturday post said.

Weather forecasts predict a high temperature of 85 degrees on Saturday, with winds ranging from 3-13 miles mph and gusts up to 25 mph, ODF noted.

“As firefighters begin mopping up the north side of the fire today, they will be aware of this potential and ready to defend the lines. Wind may also increase smoke on the fire, which is expected,” officials said.

Saturday saw smoke drifting into parts of the Rogue Valley, with the odor of smoke permeating the air, although most air-quality readings remained in the moderate range.

“Hazard trees remain a constant threat to firefighters on this incident,” according to ODF. “There are large patches of dead and dying conifer trees that have been impacting fire behavior and falling as firefighters work around them.”

Dead Douglas fir trees are the result of numerous factors, the post noted, including prolonged drought and hotter than average temperatures, as well as decades of fire suppression.

“Firefighters are aware of the falling potential and are mitigating these risks as much as possible. Rocks have also been falling down the steep slopes this fire has been burning on, and safety remains a top priority,” officials said.

More than 360 personnel are assigned to the fire, including 13 20-person crews, four engines, three bulldozers and eight water tenders. Two Type 2 and Two Type 1 helicopters remain dedicated to the fire when needed, and two Type 3 helicopters are providing full-day coverage as an air attack platform to coordinate aerial work, according to ODF.

The third Type 1 helicopter was pulled off the fire Saturday.

The Bureau of Land Management has issued a closure order for BLM-managed lands in the fire area, including Grouse Creek Road. A map and additional information is available at blm.gov/orwafire. Little Applegate Road and Applegate Lake remain open, but firefighters are working near and on the side of the road 24 hours a day, the Saturday post said.

Evacuation orders for the Jacksonville-Ruch area remain in effect, put in place by the Jackson County Sheriff’s Office and Jackson County Emergency Management. Zone JAC-434 is on a Level 1 “Be Ready” notice. Zone JAC-436 remains at Level 2 — “Be Set.” More information about zones and locations is available at protect.genasys.com/.

Fire officials on Friday increased the fire danger level for Jackson and Josephine counties from “moderate” to “high.”