They've spent thousands of dollars and man hours giving dogs new lives in the canines' own backyards. Now, the works of The Coalition to Unchain Dogs is hitting the big screen.

"As far as we knew, no one else in the country was doing what the coalition was doing," said Robert Hensley, a Coalition volunteer. "I think documentaries at their best are about making the invisible visible. I think, in part, we're showing folks a world they may not have known existed."

Robert Hensley teamed up with his wife, Lori, to shoot "Untethered." It follows the group though months of service and focuses, partly, on how the group got new ordinances passed in Durham County. Click here to read the new rules that start Jan. 1, 2010.

"We do see dogs with embedded collars," Lori Hensley said. "We do see dogs that are forgotten. But we do see people that are forgotten, too."

The Coalition to Unchain dogs now has a listserv of 150 people. On any given weekend, there are a few dozen out building fences in the Triangle area.

"I think there's a natural empathy between humans and dogs," Robert said. "We selected them for loyalty; we selected them for companionship. Over that time, we've created an animal that really fits well with us."

"Untethered" recently debuted in Durham to a sold-out audience. The Hensleys will show the film again at the Burning Coal Theatre in Raleigh on Oct. 18.

"The documentary is the story of a dog, Fluffy, who had an embedded collar," Lori said.

She said many of the dog owners are trying to help these animals but just can't.

"They want a better life for their dog. They want to do better," she said. "They welcome us into their yards. They're compassionate caring people who want help; who want to do better."

The fences these volunteers are building cost anywhere from $350 to $400. They raise money through the year at events like The Great Human Race in Durham.

"I thought about this one dog, Angel, that we found that was chained and she just had litter after litter and she couldn't care for the puppies and she'd drag the chain over them and kill them; she was just so broken," Lori said. "When we built the fence and put her in there, she just ran and jumped and rolled around. And her humans were just amazed at her personality."

"They no longer saw her as this frustrated animal at the end of a chain but this being with personality with a lot of love to share with them."

Get a sneak peek Friday at 11:00 only on NBC 17 News.