CASCADE, Idaho -- The search for missing San Diego County teen Hannah Anderson intensified Saturday afternoon as more than 150 law enforcement officials joined the effort to track the girl and her suspected abductor, murder suspect James DiMaggio.
Smoke from the state's wildfires hung heavier over the vast 2.3-million-acre Frank Church-River of No Return Wilderness, where authorities have homed in on 300 square miles for the search.
Ada County sheriff's spokeswoman Andrea Dearden said all of the tactical teams dispatched for the search effort had arrived, including numerous FBI agents. About 150 personnel -- from as far as San Francisco, Portland and Salt Lake City -- were involved in the search early Saturday, and the number was expected to increase.
Dearden stressed that although there have been no new reported sightings of Hannah or DiMaggio since a horseback rider saw them Wednesday morning, the search would continue unless investigators learned new information.
"We're going to keep looking here until we have reason to think we shouldn't," Dearden said.
The wilderness area is rugged, packed with pine trees and steep terrain. No vehicles are allowed in many areas, forcing officials to travel via horseback or search by air. The smoke from the fires has affected visibility, Dearden said, but not "dramatically."
Complicating the effort is the fact that authorities believe DiMaggio may be armed. FBI Special Agent Jason Pack said earlier in the day that only specialized law enforcement teams are being sent in.
Dearden said the search would probably be suspended overnight, citing "safety reasons."
Officials have urged the public, including campers and rafters who may be traveling through the area, to call authorities if they see any sign of DiMaggio or Hannah or notice anything out of the ordinary.
Earlier in the day, Dearden said investigators were relying on such information to help narrow their search.
Authorities did not know how far the pair might have traveled. There have been no reports of missing vehicles or rafts, she added.
The nearly weeklong search for DiMaggio, 40, and Hannah, 16, has centered on Idaho after a major break in the case Friday. DiMaggio's blue Nissan Versa — the subject of a five-state Amber Alert — was found roughly 60 miles northeast of Cascade, at a trail head leading into the wilderness.
It was "the last place you can go before you hit the wilderness and stop driving," Dearden said.
The search of the area began after what authorities initially described as a group of horseback riders reported seeing a pair thought to be Hannah and DiMaggio on Wednesday morning.
The Ada County Sheriff's Department on Saturday issued a statement saying it was a solo rider who encountered the pair, not realizing until later that day that the girl may have been Hannah.
The witness said the man and girl looked out of place in the rugged terrain because they had light camping equipment, authorities said. The witness also told authorities the girl appeared to be well.
Dearden said officials were "certainly concerned" for Hannah's safety given the environment but noted that investigators were not sure where the pair might have been going or what other supplies or gear they might have had that the horseback rider did not see.
Water and food were the primary concern, Dearden said, but also potential injuries if Hannah were to fall in the difficult terrain.
"We can't be sure what she has," Dearden said. "But of course we're concerned for her safety."
DiMaggio's car, covered in brush and lacking license plates, was being scoured for evidence Saturday, Dearden said. Authorities thought DiMaggio might have rigged it with explosives, but a bomb squad determined nothing was inside.
The search for the girl began Sunday night after the bodies of her mother, Christina Anderson, and a boy later determined to be Hannah's 8-year-old brother, Ethan, were found at DiMaggio's burning home in eastern San Diego County.
Pack, the FBI special agent, said Saturday that investigators in Idaho were in close communication with authorities in San Diego. Each level of law enforcement involved was working together, he said.
"Our focus is on the safe recovery of the young lady,” Pack said. "We're hoping to do everything we can to find them as quickly as possible."
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