DURHAM, N.C. -- Duke University is reminding hikers of its face mask policy on the East Campus and Al Buehler trails.

The policy states that trail users must have a face mask with them and put it on when within six feet of one another. However, the school has received many complaints of hikers not complying.

"We have both seen and received many, many concerns from people who have been on the East Campus Trail and the Al Buehler Trail who have seen a large number of people not wearing masks," says spokesperson Michael Schoenfeld.

The university says it will monitor the trails and could close them if people don't mask up. Administrators say the policy is even more important now that some students and staff have returned to campus for in-person classes for the fall semester.

Some compliant hikers don't understand why others don't follow the guidelines. 

"I think it's common sense. I don't begrudge it at all," says Elizabeth Jones, who walks the Al Buehler trail everyday.