A manhunt was on Tuesday for a suspect who stabbed a ranger at the Staunton State Park in Colorado, according to police.

The stabbing unfolded around noon local time in the nearly 4,000-acre park southwest of Denver, according to the Jefferson County Sheriff’s Office.

The injured ranger was taken to a hospital, but his condition was not immediately released.

The suspect fled on foot after stabbing the ranger.

A motive for the stabbing remains under investigation.

Aerial footage from Denver ABC affiliate KMGH showed heavily armed officers searching the park.

Due to the ongoing search for the suspect, Staunton State Park was closed to the public and they were evacuating visitors from inside the park, Colorado Parks and Wildlife officials said.

This is a developing story. Please check back for updates.