PORTLAND, Ore. -

Thunderstorms gathering south of an Eastern Oregon fire near the Owyhee Dam have firefighters concerned that high winds and dry fuel could breathe new life into the slowly growing blaze.

Fire officials said crews totaling about 260 people were on the fire Thursday morning. Helicopters are dumping water on it.

No structures are threatened, but the storms and high winds could change that. Flames have been reported within a few hundred yards of structures at the Owyhee State Park.

The Owyhee Fire is burning in an area of nearly 45,000 acres, or about 70 square miles. Lightning started it Monday.

Firefighters made progress against the fire Wednesday night and early Thursday morning, conducting burnout operations on fuel sources near structures, roads and power lines.