An ongoing prescribed burn is underway west of Missoula. It covers 350 acres in the Nine Mile Ranger District.

It's substantially bigger than an average prescribed burn and it has taken ten years to prepare for.

NBC Montana photographer, Marcus Chebul spent time today with District Ranger Chad Benson.

The operation includes ground crews and helicopters.

Benson says crews stay in close communication with landowners. "We're right up against a lot of homes. We really do our best to get the word out, whether it's door to door knocking or phone calls. It's sometimes hard to process that you are going to have a large fire in your backyard. We plan these things many, many years in advance."

Benson adds that weather, air particle and personnel factors all have to come together. "The reason we are in here today is that we have the alignment of both weather, people and a good air shed that allowed us to tolerate some smoke today."

Crews are trying to achieve more spacing between trees and less crown density. Benson tells us, "The reality behind it is when we are able to achieve these acres on our terms, with the right prescriptions and the time frames we want, our successes are a lot easier come by than in August when those fires don't happen on our terms at all and the outcomes can be drastically different."

The area includes the Six Mile Creek Drainage, the Frenchtown Face and the South Fork Fish Creek areas. This is an on-going burn. Rangers will post notifications on roads when conditions allow them to burn.