(05-16) 17:15 PDT Yosemite --

The first accidental deaths of the year at Yosemite National Park occurred Friday when two people died after falling in separate incidents.

A Texas professor drowned after he slipped and fell into the raging Merced River, and a Berkeley man died in a fall below Yosemite Falls. They were the first deaths this year attributed to the fast-moving water, steep slippery trails and high country danger inherent in a park that received double the normal amount of snow this winter.

Park spokesman Scott Gediman said tourists pouring into Yosemite should be aware that, as the snow melts over the next few weeks, the icy water will swell, creating dangerous swirling rapids and thunderous waterfalls that are both beautiful and dangerous.

"Anytime you have high water and a lot of visitors, you have dangerous conditions," Gediman said. "We've got slippery trails, slippery rocks and swift-moving water that can be deceiving. And we haven't even gotten to the maximum runoff yet."

At 11:30 a.m. Friday, Kent Butler, 60, of Austin Texas, slipped at the bottom of the granite steps on the Mist Trail below Vernal Fall, landed on a rock and slid into the roiling Merced River.

Butler, assistant dean of research and operations at the University of Texas, was on vacation with his family. Several people saw him slip, Gediman said, but there was nothing they could do as he was swept away in the raging, foaming water.

"He was pulled down several hundred feet," Gediman said. "His partially submerged body got wedged in the middle of the river, in view of visitors."

The horrifying spectacle remained until Saturday afternoon when rangers managed to tie a high line across the river and recover the body.

The body of James Dunbar, 35, of Berkeley was found Friday afternoon as rescuers were attempting to recover Butler's body, Gediman said. Dunbar was either hiking or running down the upper Yosemite Fall trail when he apparently tripped and hit his head on a rock. He died shortly after emergency crews reached him, Gediman said.

The last time there was this much snow in Yosemite in May was in 2006, a year that saw several fatalities and 219 search and rescue operations on the towering cliffs and thundering waterfalls and in the vast wilderness that make up the park.