A beloved dog has been reunited with his overjoyed family in Las Vegas after being missing for six years.

Willie, an 11-year-old Shetland sheepdog, went missing in April 2009 while David and Alison Marks were vacationing in the Pioche Hills, a mountain range in southeastern Nevada, KENV reported.

'While we were up in the mountains, Willie and his brother picked up on a rabbit or something and took off,' David Marks told ABC News.

'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.'

The couple posted numerous fliers and asked people around the area if they had seen or know the whereabouts of their dog.

They 'never heard back' from anyone about him 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 told ABC News.

'I couldn't believe it. It was an absolute surprise, and the perfect Christmas gift.'

He said that when they went to go pick him up, Willie 'recognized' them right away and 'he immediately came right over, wagging his tail.'

The couple heard from a family in Elko that reportedly had been caring for Willie for the past six years until he ran off again, ABC News reported.

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

'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.'

The family said that since Willie has been back home that everything feels 'complete again' and that they were 'overjoyed' and 'grateful' to spend Christmas with him.

'We've been introducing him again to everybody, but it's just like he never left,' David Marks told ABC News.

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