ALBUQUERQUE, N.M. (AP) — A homeless man who was stuck in thick mud near the Rio Grande river in Albuquerque for three days was rescued Saturday after some high school students on a field trip heard him yelling for help, authorities said.

However, the man’s newfound freedom wasn’t going to last. Police said he was wanted on a felony warrant, and they planned to arrest him after he was treated at a local hospital.

A group of La Cueva High School students and their biology teacher heard the man yelling Saturday morning from a marshy wetlands area in the Oxbow Open Space Preserve, the Albuquerque Fire Department and police officials said.

The students were in the area — about two miles north of Interstate 40 in Albuquerque — doing a school project. They called authorities and told them that the man said he’d been stuck in the river for three days and could not move, according to a police report.

Fire crews and preserve officers responded and found a “male subject stuck on a reed island about a hundred yards from the west bank of the river,” the report said.

Crews deployed an air boat and used a pulley system to lift the man from the mud and water, and up a hill.

Police later identified the man as Clayton Senn, a transient who’d been living near the river.

Authorities said they discovered a warrant for Senn’s arrest on suspicion of aggravated assault with a deadly weapon, a felony. Senn was taken to an Albuquerque hospital for treatment and was to be booked on the warrant upon his release, police said.

Details on Senn’s condition were not immediately available.