DENVER — The spirit of bipartisan cooperation may be slow to show itself at the Colorado State Capitol these days, but other apparitions roam the halls beneath the golden dome with regularity, according to a volunteer tour guide fascinated by both history and the paranormal.

“The official line has been that the Capitol is not haunted, never has been and never will be haunted,” said George Cole, who has been giving tours at the Capitol for six years. “As tour guides we are encouraged not to tell any of the things we see, but what I’m about to tell you is pretty much common knowledge. Every middle-schooler in Denver knows these stories.”

Cole said he has experienced unexplained phenomena in the marble halls of the Capitol that he believes can be traced to violent events. One of them originated in Southern Colorado with the famed Espinosa brothers, Felipe and Jose.

Historical accounts described the Espinosas as killers embittered first by the deaths of six relatives in Mexico at the hands of American fighters during the Mexican-American War, and later by the pioneer squatters who took up residence on their land-grant property in the San Luis Valley.

It was these unwelcome visitors who the Espinosas lashed out at hardest, reportedly killing about two dozen people in gruesome fashion in the early 1860s, more than a decade before Colorado attained statehood.

“It was said that they cut the heads off some of the settlers and stuck them on fence posts as a warning that this was their land and to stay out,” Cole said.

The beheadings (and a purported threatening letter from Felipe Espinosa, which some historical accounts refute ever existed) got the attention of Colorado Territorial Gov. John Evans. A $5,000 bounty was placed on the brothers’ heads.

Tracker Tom Tobin and a handful of soldiers killed the Espinosas during a shootout in 1863, and their heads ultimately were delivered to the Capitol. They were stored briefly in the treasurer’s office and later in a storage area in the basement of the Capitol for decades before being disposed of in a furnace there, according to Cole.

“At night it’s said you can hear horses’ hooves running on the yule marble in the Capitol, up and down the grand staircase,” Cole said. “It’s believed they are the Espinosa brothers’ ghosts on horseback looking for their heads.”

Deadly love triangles involving politicians have been fertile ground for ghostly legends at the Capitol, as well, Cole said.

In his book “The Ghosts of Denver: Capitol Hill,” author Phil Goldstein reports a tragic story of heartbreak involving a legislator’s mistress. The lawmaker reportedly put her up in a building near the Capitol, where she committed suicide by slashing her wrists when their affair was discovered and the politician chose his wife over his mistress. Residents of the building reported strange events in the elevator for decades. The building’s current owners chalked up the problems to a short circuit that since has been repaired.

Cole believes he has encountered the spirit of another woman whose heart was broken by a Colorado lawmaker during the early part of last century. A legislator’s wife, enraged by his affair with another woman, shot him dead at his desk, then killed herself with the same gun.

Cole said he and others have seen an apparition that he suspects is the ghost of the senator’s jealous wife.

“Sometimes in the late afternoon from the third floor you can see a white vapor that rises from the Senate and forms itself into a Victorian lady and will float to the right or left from the entrance of the Senate,” he said. “I’ve seen it. At least a half dozen tour guides I’ve spoken to have seen it.”

Cole recounted other odd happenings he has observed in the building, as well.

“I have been in the Capitol late at night, about 9:30 p.m., and if you’re quiet and you watch, you can hear strange stuff,” he said. “I heard a commotion in one of the stairwells three or four years ago. I heard a door slam upstairs. I didn’t think anybody was in the Capitol. I wandered up to check the dome, and the door that goes into the dome was opened a little so I shut it. Nobody was there. I talked to some others who worked at the Capitol who said they had noticed doors opening, lights going on at night when nobody else is there.”

Others who have spent ample time at the Capitol at night have never observed anything out of the ordinary after the politicians have left for the evening.

“I believe some people are more attuned to the strange activities than others and pay closer attention to it,” Cole said. “Some believe it, some don’t.”

Believers in ghosts and nonbelievers alike enjoy the dramatic tales of haunting, Cole, particularly around Halloween.

“We are a society that still thrills to stuff like this,” he said.