(CNN) -- In the middle of the Idaho wilderness, a man on horseback had a brief conversation with two campers. The rider's realization later that he may have been talking to California Amber Alert suspect James DiMaggio and his alleged teenage captive has now focused a nationwide manhunt for the pair on the rugged mountain area in central Idaho. 

The horseback rider saw the man and girl Wednesday and struck up a brief conversation with them, Andrea Dearden, spokeswoman for the Ada County Sheriff's Office, said Friday. 

He 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 16-year-old Hannah Anderson, she said. 

The rider's impression of the pair was "it seemed odd but nothing as alarming," Dearden 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. 

Dearden appeared to be correcting authorities' earlier reports that the suspect and girl were spotted by more than one horseback rider. 

Investigators set up checkpoints where DiMaggio and Hannah were believed to be traveling in the River of No Return Wilderness area, about 15 miles outside Cascade, Dearden said. 

Authorities haven't yet evacuated any homes or businesses, she said, adding, "We have those access points secured." 
What is the name of the teenage captive?
How old is she?
Who is the captor?
When did they talk to a man on a horse?
Who is Andrea Dearden?
Of what county?
What tip line did the man call?
Did he watch the news that night?
Did the man think it seemed odd?
Was he alarmed?
Did they exchange a lot of information?
Were the man and girl on bikes?
What area were they travelling in?
What is the nearest town?
How far away is it?
What state was this in?
Did they make access points?
Hannah Anderson
 DiMaggio and 16-year-old Hannah Anderson, she said.
16
16-year-old 
James DiMaggio
Alert suspect James DiMaggio and his alleged teenage captive
yes
a man on horseback had a brief conversation with two campers
spokeswoman for the Sheriff's Office
spokeswoman for the Ada County Sheriff's Office
Ada
 the Ada County Sheriff's Office
Amber Alert
but he called the Amber Alert tip line 
yes
after he saw a news account that night
yes
 "it seemed odd but nothing as alarming," Dearden said. 
no
but nothing as alarming," Dearden said. 
no
"They did speak and exchange pleasantries. I don't think there was a lot of information exchanged," she said.
no
The rider said the man and girl were on foot, hiking with camping gear, Dearden said.
the River of No Return Wilderness area
were believed to be traveling in the River of No Return Wilderness area, about 15 miles outside Cascade, Dearden said. 
Cascade
15 miles outside Cascade
about 15 miles
about 15 miles outside
Idaho
In the middle of the Idaho wilderness
yes
Investigators set up checkpoints 