In August last year in a remote area of Alaska the pair capped off an eight-and-a-half-year journey that saw them visit all 59 registered national parks in the United States.

While they are part of a very exclusive group to achieve the feat, their travels will be revealed for all to see through the release of a hardcover book titled The National Parks of the United States: A Photographic Journey.

The book features more than 300 of Mr Thomas’ best photos, with a section dedicated to three of America’s “forgotten” parks – a feature Mr Thomas said is “a totally unique aspect”.

CHECK OUT THE COLLECTION OF SOME OF MR THOMAS’ FAVOURITE PHOTOS HERE

“Our first trip was in December 2007 and it was so that I could run a marathon in Death Valley, it had nothing to do with photography,” he said.

“We visited four national parks on a trip just as a tourist trip. Viewing these sights, I was amazed with what we were seeing, so I started taking more photos.

“We started to go back every six months and after about four or five trips, I was getting more serious about my photography.”

Eventually, the pair decided that they would attempt to visit all 59 of the parks, a feat very few, if any, tourists have achieved.

“I don’t know anyone outside of the USA who has done it. I think it’s extremely unique, what we’ve achieved,” Mr Thomas said.

“It allows you to think of America in a different light, it’s not just the big cities,” Ms Smith added.

“It’s just beautiful.”

Their travels brought them many incredible moments, particularly at the end in Alaska.

“You wave the plane off as he flies off and hope he comes back two or three days later and that the bears haven’t got you,” Mr Thomas laughed.

The world seemed a smaller place when they met a couple at the Virgin Islands who remarkably had a photo of Lake Wendouree taken at the 1956 Olympic Games hanging on their wall.

They also met Rock Novak, the sole occupant of legendary Death Valley ghost town Ballarat (in California), and visited another namesake with just the one ‘l’ (Balarat) in Colorado.

While the book will no doubt be a popular addition to American coffee tables, the couple hope it will entice all readers to want to explore the great outdoors.

The book can be pre-ordered at here.