By Greg Botelho. Mariano Castillo and David Simpson
(CNN) -- About 250 law enforcement personnel converged Saturday on the wilds of western Idaho, doing whatever they can to track down a 16-year-old girl and the fugitive who allegedly kidnapped her.
In addition to guarding all ways out, they are trying to cover 300 square miles of rough terrain frequented by nature lovers near where the suspect James DiMaggio's car was found Friday. Its license plates removed, the vehicle was hidden by brush in the River of No Return Wilderness, about 15 miles outside Cascade, Idaho.
"We know that any piece of information, any piece of evidence, any clue that we could find could be what we need to bring Hannah home safely," Andrea Dearden, spokeswoman for the Ada County Sheriff's Office, told reporters Saturday afternoon.
Hannah Anderson of San Diego County, California, was last seen at her cheerleading practice August 3. She, her 8-year-old brother, Ethan, and her mother Christina were reported missing the next day.
Ethan and his mother, Christina Anderson, perished in a fire at DiMaggio's house in the enclave of Boulevard on August 4.
Since then, authorities have been hunting for the suspect and Hannah, with a tip earlier this week leading them to focus on the area of Idaho about 1,000 miles north of where the two died.
The discovery of DiMaggio's car there further intensified that search.
By Saturday afternoon, about 150 FBI agents from various offices, 50 to 60 personnel from state and other federal agencies, and about 60 local law enforcement were on site, according to Dearden.
There had been no more confirmed sightings of the teenager or her alleged abductor by then, with a lot of terrain to cover. Given the scope of the area, searchers won't necessarily go inch-by-inch, Dearden said, though they will "use every single resource possible."
"Whatever they feel is most effective and most useful, that's what they are going to use," the spokeswoman said.
Despite the violent death of her mother and brother, Hannah is presumed alive -- as is DiMaggio.
"We're looking for DiMaggio and Hannah," Dearden said. "And we're looking to bring her home safely."
Witness: DiMaggio had crush
A friend of Hannah Anderson on Saturday provided a clearer picture of the relationship between DiMaggio and the teen.
Marissa Chavez told CNN that she was in a car with Hannah and DiMaggio a few months ago when the 40-year-old told Hannah he had a crush on her.
He followed it up by saying if he was her age, he would date Hannah, Chavez said.
Hannah was unnerved by the comments, but did not tell her mother because she did not want to ruin the close relationship that her parents had with DiMaggio, Chavez said.
After that, however, Hannah did not want to be alone with DiMaggio, Chavez said.
In an earlier episode, Chavez recalled a trip that DiMaggio and Hannah took to Hollywood. The trip was supposed to be for one week, but Hannah told Chavez that they came back after two days because DiMaggio was upset that she wasn't paying enough attention to him.
"I don't think she would have gone willingly with him at all," she said.
Focusing the search
The suspect's car was found after a man on horseback reported he had a brief conversation with two campers in the Idaho wilderness on Wednesday. The rider's realization later that he may have been talking to DiMaggio and his alleged teenage captive has been the biggest break in the search yet.
The horseback rider was not aware of the manhunt at the time, but he called the Amber Alert tip line after he saw a news account that night and realized the pair matched the description of DiMaggio and Hannah Anderson, according to Dearden.
The rider's impression was that the pair "seemed odd," though he wasn't alarmed, she said.
"They did speak and exchange pleasantries. I don't think there was a lot of information exchanged," she said. "He left the conversation believing they were camping in the area."
The rider said the man and girl were on foot, hiking with camping gear, Dearden said.
If they are still in River of No Return, DiMaggio and his alleged captive are not necessarily alone.
Those who previously gained entry into the area, for hiking or rafting, aren't being forced to leave, the sheriff's office spokeswoman said Saturday.
Authorities are trying to talk to everyone leaving the area, to see if they saw any signs of the pair. Even given the vast area to cover and some smoke lingering from a nearby wildfire, they will comb the wilderness looking for clues -- using maps, local experts and whatever else to guide them.
"We're going to have to do this strategically," Dearden said. "We're going to have to go to the areas that make the most sense."
CNN's Michael Martinez and AnneClaire Stapleton contributed to this report.