OLYMPIC NATIONAL PARK — Firefighters will take action to limit the spread of the Paradise Fire today, park officials said.

The fire in the Queets Valley had spread to 375 acres by Thursday morning, according to Barb Maynes, Olympic National Park spokeswoman.

Firefighters are mobilizing supplies now, Maynes said this morning.

A late May lightning strike has been determined to be the cause of the blaze confirmed by an aerial flyover on Monday.

The fire is about 12 miles up the valley from the Queets River trailhead within the park boundary.

The Queets River Trail is closed at Bob Creek until further notice.

The blaze threatens no structures, Maynes said.

It is burning slowly along the Queets River near its confluence with Paradise Creek in an area of very tall centuries-old trees, making suppression activities difficult and dangerous for firefighters, Maynes said.