The Spruce Fire in Yellowstone National Park has grown to an estimated 1,164 acres as of 6 p.m. Saturday, September 12.
Since its discovery Wednesday, September 9, the lightning-sparked fire has bloomed from a tenth of an acre to 100 acres to 425 acres to its current size. The fire has been stoked by a combination of warm weather, westerly winds, and low humidity levels.
Fire crews are monitoring the fire via helicopter and report the fire is burning in a typical mosaic pattern, often found in lodgepole pine forests. Mosaic burning, in the case of the Spruce Fire, includes patchy burning in the fire’s perimeter, as well as single isolated trees and small crown fires.
Since the fire, which is burning ten miles west of Fishing Bridge and two miles south of Hayden Valley, is so isolated from visitor infrastructure, there are no closures in effect. Crews still expect the fire to burn naturally, without the need for significant intervention. As of yet, there are no trail, campground, or structure closures in place.
The Spruce Fire is expected to grow throughout today, September 13, since prevailing conditions (warm weather, winds, humidity) are expected to hold. Smoke is visible throughout the Park, especially from high points like the Mount Washburn Fire Lookout webcam and the Dunraven Pass (viewpoint pictured above).
The 5L4 fire on Promontory Peninsula is still burning at 16 acres and is not expected to grow any further. Backcountry campsites 5L3, 5L4, and 6A1 are still closed for the time being.
The fire danger in Yellowstone National Park holds at “High,” although there are no fire restrictions in place. Campfires are still permitted at designated sites in Yellowstone campgrounds, select picnic areas, and some backcountry campsites.