A helicopter crew conducted aerial operations Tuesday by dropping incendiary plastic spherical devices (PSDs) on unburned fuels in the interior of the Peavine and Poison Canyon fires, but afternoon rainstorms stopped the work midway through.

“Nature has the last word in wildland firefighting,” said acting Incident Commander Matt Way. “We met some of our aerial burnout objectives, but rain intervened before we could finish. We will try to resume operations Wednesday.”

PSDs are the size of ping pong balls and contain potassium permanganate. The machine that ejects them from a firefighting aircraft first injects glycol into each ball, and the resulting chemical reaction ignites a fire by the time the PSD hits the ground.

Aerial burnouts allow fire crews to treat fuels deep inside the perimeter of fires like the two burning in the Manti-La Sal National Forest. Given the steepness of the terrain in that part of the forest, aerial operations can clean up accumulated fuels without compromising the safety of firefighters on the ground.

“We’re eager for this opportunity to work with nature to restore the health and balance of the forest ecosystem with low-intensity fires of natural origin,” Way said. “But firefighter safety is our primary consideration.”

Each fire is approximately 20% contained, thanks to the efforts of 96 firefighters and support personnel. Continuing burnout operations may bring an increase in acreage over the next few days.

Detailed information about road and trail closures is available on the Manti-La Sal National Forest website at https://www.fs.usda.gov/mantilasal/. For delivery of email updates, visit the Manti-La Sal National Forest website and sign up in the “Stay Connected!” box.