Spencer Fry is at the Kaiser Permanente Roseville Medical Center in critical condition.
His father, Curtis Fry, believes he contracted it on the job from the cabins he and other tour guides sleep in at Bodie State Park, a ghost town about 100 miles from Yosemite National Park.
At that same tourist destination, six years ago, a person contracted hantavirus and died, according to the California Department of Public Health.
According to the CDC, people can become infected by rodents carrying hantavirus. Curtis Fry said all the guides knew there were deer mice in the cabins, and that his son could hear them running around and squeaking in his armoire.
The Department of Parks and Recreation reports they have not confirmed that Spencer Fry got hantavirus from his time at Bodie State Park. They also report there is no threat to the public.
The National Park Service reported, as of Nov. 1, 2012, at least 10 people have contracted the virus after visiting Yosemite National Park.
When Spencer Fry's family went up to visit him over the Fourth of July holiday, they said he had headaches for five days in a row, which was unusual for the 22-year-old. Regardless, he continued going on hikes with them.
When he woke up with a 104 degree fever, that's when they started suspecting he had contracted the infection.
The Fry family is asking for the community to pray for his full recovery. They are also asking for any donations on his You Caring account.
Fry's father thinks there needs to be stricter safety protocols for state park employees to prevent the spread of hantavirus.