SUNDANCE, Wyo. (AP) — Firefighters have gained about 30 percent containment on a wildfire that is threatening rural residences in Crook County in northeast Wyoming.

State Forester Bill Crapser says about 20 rural residences have been advised to evacuate.

Crapser says the fire is burning in heavy timber about 17 miles southwest of the town of Sundance, which is not threatened. About 140 firefighters supported by helicopters and air tankers are fighting the fire.

The fire was started by lightning on Tuesday and has burned an estimated three square miles.

Crapser says firefighters felt they were making progress until Friday morning when the fire began increasing in size in hot, dry weather conditions.

Gov. Matt Mead on Friday urged area residents to exercise caution. He urged people to listen to local radio for updates.

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