Lt. Jeff Kramer of the El Paso County Sheriff's Office, said he was "not at liberty" to discuss the precise point of origin of the Waldo Canyon fire, but coordinates posted on a federal fire management Web site and dispatch recordings indicate it started on a ridge along the trail, The Denver Post reported Friday.
The fire officially was reported about noon June 23. It burned 18,247 acres, killing two people and destroying 347 houses. It is 95 percent contained, officials said.
The cost of fighting the fire has been estimated at $14.5 million.
The sheriff's office said during the weekend a Crystal Park resident reported seeing smoke north of Cave of the Winds in the Pikes Peak region on June 22.
Firefighters investigated but disbanded at dusk that day.
"Could it be a campfire?" one firefighter asked on archived dispatch recordings from June 22.
A large plume of smoke developed west of the city the next day, sending firefighters scrambling to locate the fire, the Post said.
"This is the same place we had fire last night," an unidentified firefighter from the Cascade Volunteer Fire Department is heard saying in a radio dispatch. "It is on a ridge trail."
A member of the Cascade Fire Department declined to comment about the fire's first days, saying he needed approval from the federal incident team, the Post said.
The National Weather Service said skies were clear and no thunderstorms were in the area June 22-23, making it unlikely that the fire was caused by lightning.