The call for help came in the gathering darkness Monday night. Somewhere along the St. Croix River, in the dense forest near Grantsburg, Wis., a man weighing nearly 500 pounds lay injured after rocks ripped through his river tube. A rescue effort was on.

Twelve hours later -- after a hovercraft, amphibious vehicle and every other idea failed -- about 50 rescuers rescued Martin Rike from the rocky stretch of the river by pushing and dragging a makeshift raft of three canoes lashed together through ankle-deep water to an ambulance -- 3 miles away.

"Without those people, I would still be out there," Rike, a 39-year-old truck driver, said Tuesday night from his home in Pine City, Minn.

Lance Furber, a Pine City firefighter, was one of about 50 people who spent all night trying to find a way to bring Rike to safety.

"It was an unusual and difficult rescue," Furber said.

"I think everybody was concerned about his health and medical condition. The crews literally had to drag him over rocks and things like that."

Rike said Tuesday evening that he was thankful for the many people who helped in his rescue. He acknowledged that his weight made the rescue more difficult.

"I appreciate everything -- everything -- that was done for me," said Rike, who was released from the hospital Tuesday afternoon.

Following doctor's orders

Rike said he went tubing for the first time Monday evening because he was trying to follow his doctor's suggestions to undertake a fun but safe activity. He and three friends started in Danbury, Wis., and were headed several miles to the south. They were in an area about 2½ miles south of Fox Landing, Wis., when Rike's tube went flat.

"The farther we went on the St. Croix River, the worse the conditions got," he said Tuesday evening.

Rike fell on the rocks walking to shore, injuring his foot, and he fell a few more times in the tangle of brush along the shore, injuring his hip and shoulder. When he began hyperventilating, one of his companions phoned the Pine County Sheriff's Office for help about 8 p.m. Soon after, authorities in Burnett County, Wis., joined the rescue attempt.

"We got a call that a man was having a heart attack, but we had no location," said Pine County Sheriff Mark Mansavage. "He had a cell phone with poor service."

Eventually, help from the Grantsburg Volunteer Fire Department, the Wisconsin Department of Natural Resources and the Minnesota State Patrol arrived.

Rescuers found Rike about 9:30 p.m. after searching for about an hour in an area where the water is shallow and rocky and the river banks are steep, said Dean Roland, sheriff in Burnett County.

Rike was alert but dehydrated and in pain when rescue crews reached him, Mansavage said. And Furber said that Rike was happy to see the rescuers from Pine City -- he knew some of the volunteer firefighters -- and thanked them again and again for coming to help.

A paramedic stayed with Rike while rescuers tried to move him. First they helped Rike into a boat, but the boat ran aground, Roland said. Then they brought in a hovercraft to reach him, but that failed, too. An amphibious vehicle and an ATV didn't help either, Roland said. They even tried trying to get a Coast Guard helicopter with a hoist from Traverse City, Mich., to help.

Turning to an outfitter