(ONN) – Officials have a warning for people visiting Hocking Hills State Park: “stay on the trails.”

The Ohio Department of Natural Resources reports hikers fell over cliffs and waterfalls by leaving the trail during the Memorial Day weekend.

ODNR officers had to use a rope to rescue two of them.

And last weekend, a hiker had to be flown to a hospital after falling.

Hocking Hills State Park is in Hocking County in southeastern Ohio.

Within the park are more than 25 miles of hiking trails, rock formations, waterfalls, and recess caves.