Dog Missing for 6 Years Found and Reunited With Family in Las Vegas in Time for Holidays

— -- A beloved dog missing for six years has been found and reunited with his family in Las Vegas just in time for the holidays.

David Marks told ABC News today that he and his wife, Alison Marks, were "overjoyed" and "grateful" to be spending Christmas again with Willie, their Shetland sheepdog, now 11 years old.

The couple hadn't seen the Sheltie since he went missing in April of 2009 while they were all vacationing in the Pioche Hills, a mountain range in southeastern Nevada.

"While we were up in the mountains, Willie and his brother picked up on a rabbit or something and took off," David Marks explained. "Willie's brother Waylon came back, but he did not. We searched all weekend in a snowstorm in the mountains of Nevada, but we never saw any evidence that Willie was anywhere around."

David Marks said he and his wife put up fliers and asked around the area, but they "never heard back" from anyone -- until now.

"About two weeks ago, we got a call from an animal shelter in Elko, Nevada, and they said they picked up a stray, checked his microchip and found us," he said. "I couldn't believe it. It was an absolute surprise, and the perfect Christmas gift."

David Marks added that Willie "recognized us right away" and that he "immediately came right over, wagging his tail."

After a local TV station ran their story, the Marks heard from a family in Elko that apparently had been caring for him for the past six years before he recently ran off again.

"The individual caring for him said that Willie somehow got to Eureka, Nevada, which is over 300 miles from Las Vegas," David Marks said.

"The sheriff over there picked him after they found him in bad shape. He took care of Willie and nursed him back to health, so he gave him to a lady in Jackpot, Nevada, and then she moved to Elko, and he recently ran off."

David Marks joked that he's sure Willie told his Sheltie brother the whole story of his adventures the past six years and that he and his wife are curious to learn what happened.

The family said that since Willie has been home, everything feels "complete again."

"We've been introducing him again to everybody,” David Marks said, “but it's just like he never left.”