Workers unearthed a third human skeleton and four bullets yesterday at a ranch, and investigators said they expect to find up to six more bodies.

Two bodies were dug up earlier this week on the 2,880-acre spread 20 miles from the Kansas border, Kit Carson County Sheriff Sharon Heinz said.

The ranch was once owned by Thomas McCormick, 52, who is charged in a separate case with murdering an Idaho trucker who disappeared in 1983. The trucker's body was excavated last week from a field 100 miles west of Stratton after authorities were led there by McCormick's son, Michael.

The younger McCormick, 29, who is being held on stolen-vehicle charges, including the theft of the trucker's rig, told investigators where to dig on the ranch for bodies that he said had been buried over the past 15 years, officials said.

Jefferson County Sheriff George Hubbard said that rumors have circulated for years about the disappearance of farmhands from the ranch run by Thomas McCormick, who was known for hiring homeless men from Denver streets.

"These fellows seemed to disappear and we never could find them," Hubbard said. "It made us wonder if they'd been the victims of foul play, but we never could get enough evidence to go out and dig."

The Denver Post reported that the FBI once investigated a ring dealing in stolen auto parts in eastern Colorado that was believed to be tied to the McCormick ranch. The probe, which looked into the disappearance of homeless men from Denver, was dropped for lack of evidence, FBI sources said.