OLD TOWN — The source of a May wildfire that consumed 45 acres in Baxter State Park remains undetermined, but it was not caused by lightning, Maine forestry officials said.

The fire took place May 21 in the state park, which is one of the most beloved outdoor destinations in Maine.

The Maine Forestry Service said it’s asking for help from people who were hiking or fishing in the area on the day of the fire.

The fire started near the Appalachian Trail on the Penobscot River’s West Branch in an area known as T2 R10 Wels. Maine Forest Rangers and Baxter State Park personnel controlled the fire, which destroyed some buildings and infrastructure.

The fire cost more than $33,000 to suppress.