A foul smell led investigators to find at least 115 decaying bodies at a funeral home in rural Colorado that had promised “green” burials, officials said on Friday, describing the scene as “horrific.”

Randy Keller, the Fremont County coroner, said it could take months to determine the identifies of the deceased through fingerprints, dental records or DNA.

State and federal agencies, including the F.B.I., are helping, and Gov. Jared Polis of Colorado on Thursday issued a verbal disaster declaration for Fremont County to provide additional resources in the investigation into the remains found at the Return to Nature Funeral Home in Penrose, about 105 miles south of Denver.

According to a letter from state regulators suspending the funeral home’s license, the owner, Jon Hallford, spoke to a funeral home regulator on Wednesday and “acknowledged that he has a ‘problem’ at the property,” and “claimed that he practices taxidermy” there.

The letter, dated Thursday, also said that Mr. Hallford “attempted to conceal the improper storage of human remains” on the property.

Mr. Hallford could not be immediately reached at numbers listed under his name on Friday, and the funeral home’s voice mail was full.

Allen Cooper, the Fremont County sheriff, said no one had been arrested or charged. He said the owner of the funeral home, whom he did not name, had been cooperating.

State records indicate that the funeral home’s license was originally issued in 2017.

Mr. Keller said that the sheriff’s office had contacted him earlier this week about a “report of an odor” coming from the funeral home. Investigators executed a search warrant at the property on Wednesday.

Inside, “we found over 115 decedents who were improperly stored,” in a “hazardous scene,” Mr. Keller said.

“I want to assure everyone that the loved ones in this facility will be treated with the utmost care and respect,” Mr. Keller said at a news conference on Friday, adding that officials had set up a “family crisis center” and a phone number for families to call, as investigators begin to remove and identify the bodies.

Sheriff Cooper described the scene as “very disturbing” and “horrific” but declined to go into detail, saying that he wanted to avoid “further victimizing these families.”

“Our priority and our focus is on the impacted families,” Sheriff Cooper said at the news conference. “My office and our team of investigators — including crime-scene specialists, victim advocates and many others working this case — are committed to finding answers for the families as quickly as possible.”

The funeral home was part of a growing number that offer “green” burials as an environmentally sensitive alternative to funerals that require embalming fluids and elaborate coffins. In 2021, Colorado also became the second state, after Washington State, to legalize human composting to allow bodies to be turned into soil.

The Return to Nature Funeral Home offered burials without chemicals or concrete vaults, according to its website. It said that bodies could be buried in biodegradable caskets, baskets, shrouds or “even nothing at all.”

“Just you and the Earth, returning to nature,” the website said.

Joyce Pavetti, who lives near the funeral home, said her husband, Keith Pavetti, had noticed a foul stench while working outside over the last two weeks and “assumed it was a dead animal that was rotting.”

Over the last several years, Ms. Pavetti said, she rarely saw hearses coming and going or other activity at the funeral home.

“It always seemed strange,” she said, adding, “We just assumed they maybe abandoned it.”

Kirsten Noyes contributed research.