PRESCOTT, WIS. - Her auburn fur still wet from a cooling break in the Mississippi River, Autumn headed up an embankment and turned hard right on Wednesday morning, leading owner Jason Moser in their search for missing 5-year-old Scott Meyer.

After a few minutes trailing the 8-year-old golden retriever, Moser said, "I heard a little whimpering, a little crying. I saw bare skin and a diaper."

Moser sprinted toward the boy, who was tucked near a tree on a steep slope. He dropped to a knee as Scott snatched a water bottle from his hand and drank half.

Scott's rescue and reunion with his parents, Barb and Dick Meyer, was a seemingly improbable ending to a 20-hour hunt for the boy who disappeared under blistering midday sun and amid warnings about excessive heat.

The boy, who is autistic and doesn't use words, had been missing from his home just south of Prescott since midday Tuesday, when he wandered away from the family's home and large fenced yard on the bluffs over the St. Croix River.

He was found about a half-mile from home.

He was taken to Children's Hospital in St. Paul. A spokesman declined to release the boy's condition on Wednesday, but aunt Rose Poss said he was dehydrated, sunburned and suffering from bug bites and a severe diaper rash.

Moser and Autumn found him about 8 a.m. "As fast as he grabbed that water, you could see he was doing well," Moser said. "I told him, 'Let's get you back to your parents.' He didn't want to move or go anywhere. ... You could tell he was a little scared, a little weak."

Moser, who drove the 20 minutes from nearby Ellsworth to search, called 911 and shouted for help before texting his wife, Melissa, at 8:02 a.m. with the news.

The rescue crew loaded up Scotty and reunited him with his parents. Moser said he saw the initial hugs before the boy was tucked into the vehicle and taken to the hospital.

Community mobilizes

His tearful parents, who also have two older autistic sons, had appeared on television pleading for help and thanking volunteers who turned out by the hundreds. By 8 a.m. Wednesday, the roads surrounding Prescott High School were jammed with hundreds of people ready to board buses and go to the search area surrounding the family's home. The volunteers were to be sent out in shifts, staying cool in the school's air-conditioned basement on breaks. A local grocer donated water. Tubs of Gatorade sat on tables and fans blasted the hallways.

The good news, however, came fast, and by 10 a.m. buses full of would-be searchers returned to the parking lots.

Meghan Smith, 32, of Prescott, handed water bottles to those stepping off buses. She had also gone out to search Tuesday night even though she doesn't know the family.

"I think everybody put themselves into the mom's and dad's shoes," Smith said. "It says a lot about our community."

Among those searching for the boy was Melissa Miller, his pre-kindergarten teacher for the past year. Miller also taught the two older brothers and knows the family well.

"He loves music like 'The Wiggles,' nursery rhymes and the 'Wheels on the Bus,'" she said of Scott. "He's generally a happy kid, smart -- just nonverbal," she said. Miller said Scotty loves Eric Carle books, Dr. Seuss and water. "He loves to drink water, to play in water and swim," she said.

Miller said she went to search as soon as she heard. "I knew he was out there. He doesn't like to travel too far. He's one to sit down," she said, adding that Scotty would avoid the direct sunlight because he doesn't like it. "I knew we'd find him."

Autumn's big day

Moser's wife almost talked him out of bringing Autumn on the search. Melissa Moser said she worried about bringing the dog, who is a rotund 75 pounds. But Moser said Autumn looked rested and eager to go.

The Mosers have two children at home, 4-year-old Liam and 11-month-old Kage, so the couple recruited 13-year-old neighbor Megan Taplin to baby- sit and headed out.

"We were over here as soon as we could," Moser said. "There are so many bad places he could have gone. There's a train down there, the river. My son would do anything to see a train."

Moser described finding the boy as "overwhelming." He said Autumn, who has been hunting only once, likes to "kiss" kids, but he couldn't recall whether the dog approached Scotty. The Mosers said they were going to go home and relax for the rest of the day and maybe have a little celebration in a couple of days. Moser said Autumn, however, would receive her own steak or hamburger for dinner, in addition to her usual bounty of spillage from Liam and Kage.

Staff writers Katie Humphrey and Randy Furst contributed to this report. Rochelle Olson • 651-925-5035 Twitter: @rochelleolson