Fire crews made progress Thursday containing two wildland fires in Mendocino National Forest, while two of three other blazes in the Yolla Bolly- Middle Eel Wilderness were unattended, the U.S. Forest Service said.

The 50-acre Slides fire 4 miles west of Lake Pillsbury was 40 percent contained, with 65 firefighters, two bulldozers, 11 engines and a water tender at work Thursday, said Punky Moore, a Forest Service spokeswoman.

Steep terrain and burning material rolling downhill hampered suppression efforts, she said.

The 200-acre Skeleton fire, 4 miles east of Lake Pillsbury, was 50 percent contained. Firefighters were reinforcing fire lines and mopping up, with three crews, two bulldozers, eight engines and four water tenders involved.

A portion of the M3 Road from its junction with the M10 Road north 14 1/2 miles to the Lower Nye Campground was closed.

Smoke jumpers were working one of the Middle Eel Wilderness fires and the others were unattended, Moore said.

The fire information line is 530-640-1168.

You can reach Staff Writer Guy Kovner at 707-521-5457 or guy.kovner@pressdemocrat.com. On Twitter @guykovner.