A California man is still missing after being swept over a waterfall in Yosemite National Park over the weekend. Aleh Kalman, a 19-year-old from Sacramento, Calif., was at the park with a church group and was hiking on the Mist Trail when the accident occurred, according to a statement from the National Park Service.

A spokesperson for Yosemite National Park told ABC News that the search was scaled back today.

"We did a big search on Saturday and yesterday we did another big search, so today we're going into a limited continuous search," said Scott Gediman, a Yosemite National Park ranger. "We're not sending out the big search teams because the waterfalls are still flowing very strong with high water levels and swift-flowing water."

Gediman says the search is likely now a recovery effort because the place where the man fell was almost a 600-foot vertical drop. "It's almost impossible to survive," Gediman said.

Kalman's family came to the park on Saturday as soon as they were notified of the incident, according to the spokesman.

Kalman and his friends decided to swim to a rock in the river above the Nevada Fall. Eyewitnesses said Kalman attempted to make it back to land, but was swept over the fall.

Gediman said there are signs around the park suggesting people not swim in the swift rivers above the waterfalls. He said the trail in which the church group was on is the most popular trail in the park, with about 2,500 visitors a day at the peak.

"We don't recommend swimming in that river anywhere, we would assume that people who choose to swim in those areas know that if you go down, you're going to go over the side of the fall," Gediman said.

People going over the falls is a rare event, because there are guardrails in places and no-swimming signs. Three people went over the Vernal Fall in July of 2011. They were killed.