Idaho state investigators said Friday they haven’t determined exactly how last summer’s Cape Horn fire near Bayview started, even though a woman camping near the fire’s origin had fired two marine flares earlier in the day, with one “dud” landing in a rocky area near the camp, where the fire started.

The woman initially did not tell investigators she had fired the flares. She also admitted to destroying the flare gun.

After a year-long probe of the fire’s cause, the Idaho Department of Lands said the cause and person responsible for the human-caused blaze that destroyed nine homes and charred over 1,300 acres “has not yet been determined.”

“The fire investigation is deemed continuing in nature,” the agency said in a report released Friday morning.

If the state had found someone negligent in igniting the fire, that party could be held liable for the firefighting costs as well as property damage.

Public and private land burned in the Cape Horn fire, which threatened hundreds of homes, cabins and businesses and forced hundreds of people to evacuate for days. It took 12 days to contain the blaze, at a cost of about $6 million.

In an account detailed in the state’s report, Lisa Gibson and Kim Cannon had boated to a small beach between Cape Horn and Evans Landing for the weekend. The two friends boated into Bayview on July 4 to watch fireworks, then returned by boat to their campsite.

About 2:30 a.m. on July 5, a strong windstorm sent waves 5 to 8 feet high onto their beach, swamping their boat. Gibson dialed 911 at 4:12 a.m. to report their boat was swamped but they were safe.

Gibson told investigators she then decided to fire two signal flares to “see how they worked.” One was described as a “dud” that blew back to shore, landing on rocks south of the camp. The other flare went high and into the lake, she said. One witness reported seeing a flare about that time/Scott Maben, SR. More here (subscription required).