Alaska State Troopers say high winds in the Mat-Su Valley apparently flipped a trailer on the Glenn Highway, then fanned flames started by sparks at the scene into a fire that threatened several subdivisions Thursday night.

AST spokesperson Megan Peters says troopers believe winds flipped the trailer, which was being towed by a truck on the Glenn, shortly before 2 p.m. at the highway's intersection with Palmer Fishhook Road.

Mat-Su Borough spokesperson Patty Sullivan said Thursday that about 150 to 200 acres near the Cedar Hills subdivision burned in the subsequent fire, threatening at least a dozen homes in the subdivision. Two other homes, one on East Sand Point Drive and one in Big Lake, reportedly burned in separate fires earlier Thursday afternoon according to Central Mat-Su Emergency Services.

The fires temporarily closed the Glenn near Palmer Fishhook for several hours Thursday, with several Valley roads also closed in the area as firefighters worked late into Thursday night to contain the blazes. Cedar Hills and parts of the Valley Trails subdivision were evacuated, with residents of Cedar Hills eventually allowed to return to their homes at about 10 p.m.

Norman MacDonald with the Alaska Division of Forestry says a broad swath of Southcentral emergency responders helped contain Thursday’s fires, including fire crews from Palmer, Butte, Central, West Lakes, Anchorage, Chugiak and the division, as well as area police departments and Alaska State Troopers.

“Division of Forestry (DOF) firefighters from offices in Fairbanks and Glennallen, and firefighters from (the Bureau of Land Management) Alaska Fire Service in Fairbanks, gathered their gear and plugged in their engines, some in temperatures as low as -40F,” MacDonald wrote in a Friday statement.

According to MacDonald a total of six fires spread into wildlands Thursday, from ignition sources including the Glenn incident, two structure fires, a burn barrel, a burn pile and a power line. He warns that fire danger in the Mat-Su Valley remains high Friday.

“The current conditions are such that, no matter what the source, it only takes a spark to start a wildland fire,” MacDonald wrote. “Low to no snowpack combined with strong winds and low humidity have created the dangerous fire situation that warrants extra caution by residents.”

Valley residents are urged to call 911 upon spotting any newly started fires, as well as avoiding open burning, the use of burn barrels or any activity that could cause sparks. Drivers should look out for fire responders still in the region, making sure to turn on headlights and slow down when passing them on the road.

A red flag warning, for conditions including winds over 25 mph and relative humidity below 15 percent, remains in effect for the Matanuska Valley until 4 p.m. Saturday.

 Contact Chris Klint