BECKWOURTH (AP/CBS13) — Firefighters battled several wildfires in Northern California on Thursday as forecasts called for a new round of dangerously hot and dry weather throughout much of the state.

Campgrounds and residences around Frenchman Lake in the northern Sierra Nevada were under evacuation orders due to increased activity of a pair of lightning-sparked fires near the popular reservoir in Plumas County.

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The Beckwourth Complex covered nearly 6 square miles (15.5 square kilometers) and was 30% contained, according to Plumas National Forest officials.

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In the region between the Oregon border and the northern end of the Central Valley, the big Lava and Tennant fires were significantly contained but progress was slower at the Salt Fire, where evacuations of nearby communities remained in effect.

The nearly 20-square-mile (51-square-kilometer) Salt Fire was 35% contained after burning 41 structures since June 30, according to Shasta-Trinity National Forest officials.

In Mendocino County, firefighters stopped the movement of a fire that erupted in vegetation Wednesday afternoon, destroyed one structure and threatened 80 others, Cal Fire said.

Forecasters, meanwhile, warned that strengthening high pressure over California will bring widespread triple-digit heat over coming days.

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Copyright 2021 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.