A combination of the recent earthquake and heavy rains has wreaked havoc at Tonto Natural Bridge State Park north of Payson.
The park is open after being closed for a week, but only one of four trails is currently open to the public.
A giant boulder fell on the entrance road which necessitated closing the park from Feb. 3 to 11.
The boulder, the second of two that fell on the road, was moved by a crane on the morning of Feb. 11. It weighed 18,200 pounds, according to the crane that moved it.
"We know because the crane has a weight thing on it so they don't overload it," park volunteer Dick Maloney said.
A second major event occurred sometime during the night of Feb. 14 or 15 when two chunks of rock, one the size of a car, broke off from the cliff alongside Gowan Loop Trail and crashed onto the trail. That trail and the other two that go to the creek bottom (the Pine Creek and Anna Mae Deming trails) have been closed pending an evaluation of a large crack in the face of the cliff.
"There is a crack that goes from the top to the creek -- a very significant crack," park ranger Cathe Descheemaker said. "It appears as though it may need to be blasted to make it safe."
The Pine Creek and Deming trails are actually safe, according to Descheemaker. They were closed as a precautionary measure to keep visitors from getting too near the crack and because Pine Creek is currently running very high.
The crack was checked a little over a year ago by a team of geologists. Rick Toomey, science and research manager for Arizona State Parks, was among them.
"I'm not certain we can say any type of rock in a natural setting is safe," Toomey said. "On some time frame that piece was absolutely going to fall, but (the question is) whether that time frame was going to be in a year or two or in 1,000 years.
Both Descheemaker and Toomey believe it was a combination of the recent rains and the 3.9 earthquake that occurred 30 miles from the bridge earlier this month that caused the rocks to break loose.
"The rain plus the earthquake will certainly contribute to which pieces are stable or unstable," Toomey said.
The rock that broke off is the same that formed the bridge over a period of hundreds of years.
Despite the closure of the three trails, this is a great time to visit the park, according to Descheemaker. "Viewpoints 1, 2 and 3 are open and the Waterfall Trail is open," she said. "Plus the creek is at an all-time high, so it is absolutely beautiful to see it running like this."
Visitors also can see the 9-ton rock that fell on the entrance road.
"They brought it down to the entrance to the parking lot," she said. "It's going to be a conversation rock. It caused us to close for a week, so it was a very expensive boulder."
Located 10 miles north of Payson on Highway 87, Tonto Natural Bridge State Park covers 160 acres in a small, picturesque valley surrounding Pine Creek. The bridge itself -- 183 feet high with a 400-foot tunnel that measures 150 feet at its widest point -- is thought to be the largest travertine bridge in the world.
The park is open daily from 9 a.m. to 5 p.m. Entrance fee is $3 per person, with children under 14 free.
For more information, call the park office at (928) 476-4202 or the gift shop at (928) 476-2261.