Updated at: 08/29/2013 4:35 PM
(AP) BISBEE, Ariz. - A 60-year-old National Park Service employee was critically injured in an apparent assault in southeastern Arizona, and her government-owned truck was later found in a border town about 40 miles away, authorities said Thursday.
Karen Gonzales, a uniformed maintenance worker with the Park Service and a longtime seasonal employee, was found unconscious Wednesday afternoon in a picnic area restroom at Chiricahua National Monument.
Gonzales suffered head trauma and was airlifted to a Tucson hospital, where she remained in critical but stable condition, Park Service spokeswoman Michelle Fidler said.
Gonzales’ government vehicle was found several hours later in the city of Douglas by tracking the worker’s cellphone, which was still inside.
Authorities were processing the vehicle Thursday searching for clues in the case, Fidler said.
"It appears to be an assault and robbery," Fidler said. "We’re still investigating all leads."
No suspects have been arrested or identified, authorities said.
Perryn Collier, a spokesman for the FBI in Phoenix, said the agency was assisting in the investigation being conducted by the Cochise County sheriff’s office and Park Service law enforcement officials.
Sheriff’s spokeswoman Carol Capas said the pickup truck was found in the middle of the border town of Douglas. There was no immediate evidence that whoever abandoned it had crossed the border into Mexico, she said.
Douglas is about 40 miles south of the national monument, which is in mountains and desert on the east side of a broad valley that runs north from the U.S.-Mexico border.
The region is used by drug smugglers and people entering the United States illegally.
"We do have significant foot traffic and vehicle traffic that’s attributed to illegal activity," Capas said.
Deputies were working closely with federal and state law officers to "identify the suspect(s) who apparently seriously injured a federal employee," Cochise County Sheriff Mark Dannels said in a statement released by his office.
The monument was the site of the still-unsolved 1980 disappearance of a Park Service ranger, Paul Fugate, who was last seen when he went on foot patrol.
Also in the region, the unsolved shooting death of a Douglas-area rancher, Rob Krentz, helped spur passage of a 2010 Arizona law targeting illegal immigration.
Krentz was gunned down in March 2010 while checking water lines on his property. Authorities believe _ but have never produced substantive proof _ that a scout for drug smugglers killed Krentz.
The U.S. Supreme Court struck down some parts of the 2010 law two years later, including the requirement that immigrants obtain or carry immigration registration papers. But the high court upheld a requirement that Arizona officers question the immigration status of those suspected of being in the country illegally.
(Copyright 2013 by The Associated Press. All Rights Reserved.)