For more than a century, the original state penitentiary at Deer Lodge, a stark stone fortress, housed Montana’s criminals.

For Ellen Baumler, interpretive historian at the Montana Historical Society, it represented a “rather dark chapter” in the Treasure State’s history — and a story that had never been fully told.

“It’s not a pretty story,” she told an audience Saturday at the museum. “None of it is a pretty part of our history.”

But it was a tale that needed telling, so Baumler collaborated with society photographer J.M. Cooper to produce “Dark Spaces: Montana’s Historic Penitentiary at Deer Lodge,” a look at the prisoners, wardens, riots and occasion escapes that defined the prison from its 1870 opening as a federal territorial institution to its 1979 closure.

Baumler and Cooper use a mix of archival and original photographs, along with stories coaxed from historical records, to shine a light inside the old stone walls and tiny two-person cells. Cooper’s black-and-white photographs render the sense of despair he and Baumler found within those bars and stone.

It was a place of desperation for many men and women — some of whom shouldn’t have been sent there in the first place, and some who kept too long for reasons political or otherwise.

Take the case of Thomas Riley, who entered prison in 1898 a young man and grew old there. He murdered a bank president he thought had wronged him, but was kept at Deer Lodge long after he should have been paroled.

Officials didn’t release him, fearing a backlash from the Anaconda Company, with which Riley’s victim had connections. Petitioners failed in their efforts to prompt his release.

Finally, in 1937, Gov. Roy Ayers visited Riley and “found all the bitterness dried up in him” and gave him a full pardon. Riley died just a few months later, after spending nearly 40 years in the facility.

Then there’s the story of Bessie Fisher, who was sent to prison in 1901 for second-degree murder. Baumler thinks hers is clearly a case of self-defense — Fisher shot a knife-wielding woman twice her size. Baumler attributes the conviction to Fisher’s all-male jury. Until the 1930s, women weren’t allowed to sit on juries.

A fellow named Turkey Pete was one of the prison’s longest-serving inmates. Mentally ill, he thought his sister was Queen Victoria, and the prison actually printed fake checks for him to purchase properties within the walls in fake real-estate deals. Pete had the run of the place, and officials kept him at the prison until his death because they didn’t think he would survive in the outside world. His was the only funeral ever held at the prison.

Though some people met their end at the prison, only two men, charged with instigating a riot in 1908, were executed there. The warden waiting until the men, who had been injured in the melee, returned to health before ordering their hanging. For decades, Montana law dictated executions be carried out in the county where the crime was committed.

Cooper has published the only photo of the “death tower,” the site of a murder-suicide following riots at the prison in 1959. He also photographed the “hole,” a dungeon-like isolation cell where one prisoner died on Halloween in 1966. Opinions vary on the nature of his death — prison officials claimed he overdosed on drugs, prisoners believed he died from overexposure to heat from the steam pipes located in the tiny room.

Baumler became interested in writing about the prison while researching a ghost story for a national anthology. She’s been to the jail three times with paranormal investigators, but hasn’t experienced any ghostly encounters. She shared stories reported by tour guides and tourists — strange walls of heat, the sound of footsteps, shouting and laughter in empty hallways.

“It’s a weird place, and there’s a weird energy there,” she said.

“Dark Spaces: Montana’s Historic Penitentiary at Deer Lodge” is Baumler’s fifth book and Cooper’s first work. Published by the University of New Mexico Press, it’s available at the Historical Society bookstore and at shops across Helena.

Reporter Larry Kline: 447-4075 or larry.kline@helenair.com