Denali National Park officials say a “massive” landslide has blocked Denali Park Road at Mile 37, beyond the section currently open to the public up to Mile 30 and the Teklanika Rest Area.

Park spokesperson Kris Fister says the slide was discovered by two of the park's road crew supervisors west of Tattler Creek near the road’s approach to Sable Pass Wednesday. While material was released from 500 feet above the road and some ended up south of the road, none of it reached Igloo Creek.

“The slide, which consists of an estimated 30,000 yards of rock and soil, covers approximately 200 feet of the road in depths of up to 35 feet,” Fister wrote in a Friday statement.

While some slides commonly occur on the park road, Fister says this week's event is markedly larger than usual.

"Not to this degree -- we certainly, occasionally will get some rocks," Fister said.

According to Fister, the crew supervisors who found the slide say it's the biggest one they've seen in recent memory, since a 1989 slide in the Polychrome area.

"The last one they can remember that was anywhere close to this was in the late 1980s," Fister said. "More of the road was involved, but not nearly as much material."

Park staff assessed the slide Thursday, and a road crew is expected to begin clearing it Friday.

“Crews will work seven days a week in order to accomplish as much as possible while the unseasonably mild weather conditions last,” Fister wrote. “Work will continue in the spring as needed.”

Fister warns bicyclists and hikers on the park road to avoid the work zone, due to the instability of the slope.