DENVER—The deadly wildfires that struck Colorado this week came on the heels of a winter that dumped record amounts of snow at some ski resorts and left behind an above-average mountain snowpack.
While much of the high-mountain snow remains, the three fires that erupted Tuesday swept across valley floors, plains and hillsides where the snow has vanished but the grass and shrubs are still dormant and dry.
“We’re in that intermediate period, when snow has melted and grass has not yet greened up. So it sets the conditions right for fast-moving, short-duration fires, much like what we saw in Colorado,” said Steve Segin of the Rocky Mountain Area Coordination Center, which coordinates state and federal firefighting efforts.
The fires quickly burned across a total of nearly 29 square miles. Much of the state was under a National Weather Service red flag warning Tuesday, signifying high fire danger because of low humidity, above-average temperatures, and high winds.
Nolan Doesken, state climatologist at Colorado State University, said the March-April period “is one of the more dangerous ones for grass fires.”
“As we get later into spring, the green grass starts greening up and growing,” he said. “That lowers the risk of rapid-spreading wildfires until the grasses of spring dry off in the summer. By then, the winds are less.”
Two firefighters were killed at the fire near the small town of Ordway, 120 miles southeast of Denver, and a firefighting pilot was killed at a fire on Fort Carson about 60 miles south of Denver.
The third fire was near Carbondale, in the mountains about 120 miles west of Denver.
The Ordway and Carbondale fires were fully contained Wednesday night, thanks to calmer winds, cooler temperatures and new snow.
Overnight snow helped firefighters extend containment lines at the Fort Carson fire to 50 percent, up from 10 percent the night before.
The causes of the Fort Carson and Ordway fires were still under investigation. The National Weather Service reported no lightning strikes in either area on Tuesday.
Garfield County sheriff’s officials say the fire near Carbondale started after high winds exposed an ember from a property owner’s controlled burn.
No burn ban was in effect, but Carbondale Fire Chief Ron Leach said his department had not issued any of the required permits for a controlled burn that day. The investigation was continuing, and no one had been charged.
The 1 1/2-square-mile Carbondale fire damaged two buildings and slightly injured a fisherman before it was fully contained. Leach estimated firefighting costs were at least $100,000.
Pilot Gert Marais of Fort Benton, Mont., was killed Tuesday when his single-engine plane crashed after dumping fire-retardant slurry at the Fort Carson fire, which had burned about 13 1/2 square miles.
Marais, 42, worked for a Sterling, Colo., company that supplies aerial firefighting services to the Colorado State Forest Service.
National Transportation Safety Board air safety investigator Aaron Sauer said Thursday that Forest Service personnel reported winds ranging from 35 to 45 mph at the time of the crash, but investigators were still interviewing witnesses, studying the wreckage and reviewing records.
Marais’ pilot records showed he had more than 10,000 flight hours, Sauer said.
A preliminary report on the crash is expected next week, but a determination of what caused the crash could take months.
Volunteer firefighters John Schwartz, 38, and Terry DeVore, 30, were killed at the Ordway blaze on Tuesday when their fire truck plunged into a ravine under a two-lane wooden bridge built in 1937 that had been damaged by flames.
It wasn’t immediately known whether the bridge on Colorado 96 collapsed due to the fire or the weight of vehicles.
Highway crews installed culverts and a temporary road surface to carry traffic over the ravine until a permanent replacement is built, Colorado Department of Transportation spokeswoman Stacey Stegman said.
The Ordway fire burned 14 square miles, destroyed at least eight homes and prompted authorities to order all 1,200 residents to evacuate.
