Garrett Hand, 25, and girlfriend Jamie Neal, 25, of Sacramento have not been seen or heard from since Jan. 25 when they left Cuzco, Peru, to ride to Lima, The Contra Costa (County) Times reported Tuesday.
The daily progress of their bicycle trip, which began in November in Buenos Aires and taken them through Argentina, Chile and Peru, had been charted in regular Facebook entries, the last on Jan. 25.
"I really want to make this perfectly clear. The generosity, love and caring showed by so many people -- family, friends, people in Chile and Peru -- it makes you hopeful," said Francine Fitzgerald of Concord, Calif., Hand's mother.
Leslie Goodman, information officer of the U.S. Embassy in Lima, said officers at the embassy are in contact with the families and are providing assistance. She added Peruvian police are working with the embassy in the search for Hand and Neal.
The newspaper noted the embassy recently warned Americans to beware of kidnapping threats in the Cuzco area.
Notable deaths of 2014 [PHOTOS]