UPDATE: Four mountain bikers were rescued from Catalina State Park Sunday.
According to PCSD Deputy Cody Gress, the group of four went off the trail and became lost.
Initially, officials reported missing group as hikers. News4Tucson has since learned the group was mountain biking.
PIMA COUNTY- The Golder Ranch Fire District and the Pima County Sheriff's Department are working to rescue hikers in Catalina State Park.
According to Deputy Cody Gress, with PCSD, hikers were off of the Golder Ranch trail head, near Sutherland Trail, when they got lost.
Gress said it's unclear how many people were in the group. The hikers called to report they were lost, without food or water. The hikers had patchy cell phone service and ran out of phone battery.
As of 7 p.m., one hiker was found, said Gress. He said they are searching for the other members of the group.
"We will keep going (searching) until it is unsafe to do so," said Gress.
He said they plan to deploy an aircraft shortly.
Stay with News4Tucson for updates.