LAS VEGAS -- The main highway between Las Vegas and Reno was damaged and closed early Friday following a magnitude 6.5 earthquake in a remote area of Nevada that a researcher called the largest quake in the state in 65 years.

No injuries were reported, but Nevada Highway Patrol photos showed cracks on U.S. 95 that Trooper Hannah DeGoey said were caused by the temblor a little after 4 a.m. west of Tonopah.

The area is an active seismic region, said Graham Kent, director of the Nevada Seismological Lab at the University of Nevada, Reno. He compared the Friday event with twin December 1954 earthquakes at Fairview Peak and Dixie Valley. Kent said those temblors, occurring four minutes apart, were magnitudes 7.1 and 6.8. Other sources put their magnitudes at 7.3 and 6.9, respectively.

The U.S. Geological Survey reported the the temblor struck at 4:03 a.m. about 35 miles (56 kilometres) west of Tonopah and just east of the Sierra Nevada range. The quake was upgraded after being initially reported at 6.4-magnitude.

It was centred about 4.7 miles (7.6 kilometres) deep, the agency said, and dozens of aftershocks were recorded. Kent said a 5.1 magnitude aftershock struck about 30 minutes after the initial quake.

State troopers and sheriff's patrols from Esmeralda and surrounding Mineral and Nye counties checked highways for possible damage. A sheriff's dispatcher in the historic mining boom town of Goldfield said the 112-year-old Esmeralda County Courthouse escaped damage.

Nye County sheriff's Capt. David Boruchowitz reported no damage at the Mizpah Hotel and Clown Motel, two landmark businesses in Tonopah, a mining hub about halfway between Las Vegas and Reno.

Keith Hasty, a Tonopah gas station employee, told the Las Vegas Review-Journal that groceries were shaken off shelves and that residents said their televisions shook.

Nye County spokesman Arnold Knightly reported broken storefront glass, stress cracks on asphalt streets, loose hanging signs, items knocked off shelves and minor lifting of sidewalks.

“Overall, everything appears to be sound at this point,” Knightly said. “”However, we have learned that other than obvious earthquake damage some damage is discovered later.“

Last July, a 56-year-old backyard mechanic was found dead in Pahrump four days after strong quakes struck near Ridgecrest, California, about 150 miles (240 kilometres) away. Investigators said it appeared a Jeep he was repairing wobbled off its support jacks.

State seismic network manager Ken Smith noted that Friday's earthquake happened a few miles east of the site of a magnitude 6.2 temblor in July 1986 in California's Chalfant Valley.

Larger earthquakes in the region in the last century included a 6.5-magnitude temblor in 1934 and a magnitude 6.8 quake in 1932, the state seismology lab said.

A 6-magnitude earthquake in February 2008 damaged hundreds of structures in the northeast Nevada town of Wells, including its historic El Rancho Hotel and Casino. Officials recently announced plans to restore the hotel.


Associated Press writer Paul Davenport in Phoenix contributed to this report