The Fern Lake Fire in Estes Park, Colo., has crossed to the southern side of Spruce Creek, spurred on by red flag conditions, Rocky Mountain National Park officials reported Tuesday (Nov. 27).

The fire, west of Moraine Park, was mapped Saturday at about 1,370 acres. Strong winds and low humidity have increased the fire activity. Ground attack has been difficult for firefighters because much of the blaze — fed in part by beetle-killed trees — is in steep, rugged terrain. Use of a helitanker was limited Tuesday due to the wind, the Longmont Times-Call reported.

Smoke from the fire was visible in several places along the Front Range. A fire and smoking ban is in effect in the park’s backcountry until further notice. Moraine Park Campground is still open and campfires in grates are allowed there.

Trails in the immediate area of western Moraine Park are closed to hikers, including: Fern Lake Road beyond the winter parking lot, Fern Lake Trail all the way to Lake Helene, the Cub Lake Trail from the trailhead to The Pook, and the Mill Creek Trail from the Mill Creek Basin campsites to the Cub Lake Trail. Hikers on closed trails will be ticketed.

Information about the fire is available at inciweb.org/incident/3294 and at the parks’s website,www.nps.gov/romo. A recorded fire information number can be called at 970-586-1381.