Nearly 70 children and counselors have been evacuated from a summer camp in the Colorado mountains after tests showed trace amounts of methamphetamine in three buildings.

The National Farmers Union, which owns the site, said all 67 campers and counselors were safe. They were taken Wednesday to nearby Platte Canyon High School, where they will finish the camp.

The camp is near Bailey, about 35 miles southwest of Denver.

Farmers Union Vice President Clay Peterson said Thursday his organization was trying to determine how the methamphetamine got there.

Court records show the previous caretaker had been arrested in April on drug and weapons charges.

Peterson said the camp had been searched at the suggestion of its new caretaker, who is a sheriff's deputy.

"We did the tests, and we got surprising results," Peterson said.

Peterson said the Farmers Union was told there was no health risk but that the group decided to move campers anyway. "We just didn't want to take any risk," he said.