San Juan, Puerto Rico ? Rescuers found the body of an American student Monday in a river, days after he and another student lost their way in Puerto Rico’s dense northern forests.

The body of Kristopher Reilly, 24, of Miami, was found trapped between several rocks in the Tanama River, police spokeswoman Wanda Vazquez said. Colin Mike Ewers, 21, of Bloomington, Minn., still was missing. Vazquez had mistakenly said earlier that Ewers’ body had been found with Reilly’s.

Reilly studied at the New College of Florida in Sarasota, Fla. Ewers is a student at Carleton College in Northfield, Minn. Police said earlier the men were from the University of Akron in Ohio.

Both were taking part in a 10-week astronomy program to gather data from the noted radio telescope at Arecibo, 45 miles west of the capital of San Juan, police said.

The students had been missing since Saturday, when they trekked into the woods after visiting the telescope. The river, with rough rapids, is surrounded by thick brush and steep cliffs. Reilly’s body was found in about 15 to 20 feet of water, said Delyris Aquino, spokeswoman for the Puerto Rico Emergency Management Agency.

A third student, Carroll Weiner, went with them but managed to find her way back and sought help late Saturday, Aquino said.