The fresh scar caused by the rock slide is visible in this image taken on June 28, 2013. NPS photo.

A section of the Jones Hole Trail in Dinosaur National Monument remains closed to hikers and anglers until geologists can determine whether a cliffside has stabilized after releasing several rock slides last month.

The closed section runs from the Park Service/U.S. Fish and Wildlife Service fish hatchery boundary to Ely Creek.

A Park Service geomorphologist is expected to visit the site this week to try to determine the potential for more slides in the immediate future.

"We want to get the trail open again as soon as possible, but we also need to take these necessary steps to help ensure public safety," said Monument Superintendent Mary Risser. "We appreciate everyone's continued compliance with closure notice."

A determination on the potential for reopening the area will be made after the site assessment.

The first reported rock slide occurred on Tuesday, June 18. A large slab of rock broke free from a cliff face just a short distance inside the monument boundary, less than a quarter-mile from the Jones Hole Fish Hatchery. After receiving reports, park rangers checked the scene and did not see any further activity.

On Thursday morning, June 20, another small slide occurred. Then near noon, Mountain Time, a much larger slab of rock broke free and tumbled to the stream below. A large debris field formed below the slide site. The slide was large enough to send large boulders, the size of a pickup truck, across Jones Hole Creek before coming to rest against trees by the hiking trail.

No injuries were reported as a result of the slide. The area that broke free from the cliff was roughly estimated to be 100 feet high by 50 feet wide with a thickness of 10 feet or more. The slab fell over another 400 feet to the stream below. Numerous trees were knocked down during the event including several across the trail.

Large cracks are visible in the rock remaining attached to the cliff. Staff at the fish hatchery have reported seeing a couple of small rocks fall from the cliff face. Due to the potential for more falling rock, the area remains closed until further notice.

If necessary, National Park Service Rangers will issue citations to persons violating the terms of this closure under authority of Title 36 Code of Federal Regulations 1.5(a)(1). The park asks for everyone's cooperation to protect both visitor and staff safety.

The Jones Hole Trail is a popular hiking trail that connects the Jones Hole Fish Hatchery with the Green River. It is approximately 4.25 miles long one way. The area is also very popular with anglers due to the access to Jones Hole Creek.