ANCHORAGE, Alaska — The nation’s most expensive wildfire this year is one that has been burning for months on Alaska’s Kenai Peninsula.

The Swan Lake Fire has so far cost about $46 million to fight, according to the National Interagency Fire Center in Boise, Idaho.

That price tag puts it ahead of the Walker Fire in California, which the Idaho center says cost about $29 million to fight. A fire in Montana cost about $6 million, and one in Idaho cost about $5 million to battle.

Alaska’s fire started by a lightning strike in June in the Kenai National Wildlife Refuge. Rain in late July reduced fire activity, but it flared again in August in hot, dry conditions.

Residents of Cooper Landing were told to be ready to evacuate if needed, but that restriction was lifted Sept. 17. Smoke from the fires enveloped Anchorage at times, leaving the city hazy and smelling like a campfire.

Fire officials say that as of Thursday, the fire has burned more than 261 square miles and was 57 percent contained. There are 265 firefighters battling the wildfire.

Hundreds of crews were cycled in and out of the Lower 48 to battle the blaze.

Generally, costs tend to increase on large fires with large numbers of crews, planes and other air support are used, and there are homes nearby that need protection, National Interagency Fire Center spokeswoman Jessica Gardetto told the Anchorage Daily News.

While costly, it’s not Alaska’s most expensive fire once you factor in inflation. That distinction goes to the Swanson River Fire, which burned 50 years ago, also on the Kenai Peninsula.

“That fire cost over $9 million in 1969,” said Tim Mowry, a spokesman for the Alaska Division of Forestry. “When you punch that into the whole inflation calculator, it came up $63 million.”