Firefighters continued to work on two wildland fires Sunday in the steep, rugged mountains of Northern California.

Firefighters continued to work on two wildland fires Sunday in the steep, rugged mountains of Northern California.

The Red Rock fire, burning in the Marble Mountain Wilderness south of Happy Camp, sent smoke into the Rogue Valley Friday evening. The fire had grown to about 700 acres by Sunday, Forest Service spokesman Tom Lavagnino said in a media release.

The fire was burning south of the Lover's Camp trailhead in the Red Rock watershed of the Klamath National Forest.

The fire burned actively Friday, driven by strong winds, and smoke could be seen above the Siskiyou Mountains.

The fire was started in June as a prescribed burn to reduce heavy fuels and restore meadow systems and wildlife habitat within the wilderness. Lavagnino said unexpected winds and hot, dry weather helped the fire grow until it was beyond the ability of local firefighters to control it.

No structures are threatened.

A fire in California's Siskiyou Wilderness, south of Cave Junction and east of Crescent City, had grown to 150 acres by Sunday. The Harrington fire started Aug. 2 from a lightning strike and is burning east of Harrington Mountain, in the Six Rivers National Forest. No structures are threatened.