POST FALLS - Firefighters spent Tuesday mopping up the 10-acre wildfire that started near Q'Emiln Park on Monday, and a formal investigation is likely to start today.

"People will continue to see smoke and maybe even occasional flames into (today)," said Chief Dan Ryan, of Kootenai County Fire and Rescue. "But the Idaho Department of Lands will be up there every day, and they won't call the fire out until they have observed three days without any activity."

Ryan said residents were still reporting seeing smoke on Tuesday, but there is no need to do that "unless they see major flames or something."

Because no structures are involved, the IDL will finish mopping up the hot spots, Ryan said. The interior of the fire is likely to continue burning until firefighters ensure that the perimeter is dead out.

Ryan said the cause of fire has not been determined, and his fire marshal will be joining Shane O'Shea, assistant fire warden for the IDL, in a formal investigation of the fire.

"Some of the crew came upon what may be evidence," O'Shea said Tuesday. "We will start a formal investigation into that (today)."

O'Shea declined to say what the evidence was. Ryan also declined, adding details will be released after the investigation.

Investigators will go through a process of eliminating potential causes.

"At this point, there is a pretty good chance it was human caused," Ryan said. "It is pretty rocky terrain, so there is a possibility that it could be a holdover fire from the lightning we had last week - there is a very slim chance of that, but we just don't know yet."

Ryan said landowners in the area told him that they are routinely kicking people off the property - which is privately owned - but adjacent to the Q'Emiln hiking trail system.

There is locked, gated access to the area around the rocky bluff where the fire started, but it is accessible by motorcycles or ATVs.

"But I don't know, it's pretty rough terrain up where the fire started," he said.