Witnesses say Ramina Badal, Ninos Yacoub, and Hormiz David went over Vernal Fall after posing for a picture.
Thursday, a search crew from Marin County joined the effort to find them. They happened to be training in the park. But so far, search teams are only able to walk along the Merced River because it is too dangerous for divers to enter the water.
Rangers say if they don't find the bodies by the end of this weekend -- they will scale back the search and wait for water levels to go down.