BOULDER COUNTY, Colo. — Two people found human remains while hiking in Boulder County Monday, according to the county’s sheriff’s office.

Shortly after 1 p.m. Monday, the Boulder County Communications Center received a call from the hikers reporting they had found a skull, likely from a human, near Lefthand Reservoir. The reservoir is located in the Brainard Lake Recreation Area in an unincorporated part of the county.

Later Monday afternoon, deputies joined the hikers and went back to the area where the skull was found. However, the hikers were unable to direct the deputies back to the specific spot where the remains were located, according to a statement from the sheriff’s office released Friday.

On Tuesday morning, staff from the sheriff’s office, the coroner’s office and Front Range Rescue Dogs searched the area again.

“They were able to use a photo that the hikers took to locate the remains, and while searching the area, found additional remains. They were able to confirm that the remains are from a human,” the sheriff’s office said.

The Boulder County Coroner’s Office is working to identify the remains and determine a cause of death.