Oliver's luggage typically includes a small cage with a litter box, a hammock, blanket, and a harness. He even has his own little tent for camping trips.

Oliver is truly the perfect, all-around American guy.

He's bagged 11 mountain peaks in the US. He enjoys the changing colours of the leaves in the autumn. He's described repeatedly as "super chill".

He's also a ferret.

Lauren Smith, a paramedic in Denver, impulsively bought Oliver when he was a baby nearly five years ago while living in Texas. Three years ago, the two went on their first hike together and Smith decided to create an Instagram at the suggestion of a friend. She was only expecting five friends to follow, but now her follower count is nearly 6000.

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The two moved to Broomfield, Colorado two years ago. Since then, Oliver and Smith have travelled around the state and country, including trips to Utah, Wyoming, and New Mexico.

"When he was a baby, he had a whole lot of energy, super high maintenance," Smith said. "He tore up my couch." She needed to do something to burn off that energy.

So, she thought, "if it works to take a dog to a dog park and let him run around a bit, maybe it'd work with a ferret".

Smith began harness-training Oliver. Although he initially "played dead", Oliver eventually got used to the harness (some treats helped). He accompanied Smith on a couple of trails in Texas but once the two moved to Colorado, where the temperatures are cooler and trails abundant, his hiking took off.

Oliver has been to nine national parks in six states. He tried camping for the first time in August 2018. In June 2019, he started kayaking. Smith is looking at trying stand-up paddleboarding with Oliver this summer.

The ferret has had photos taken at Crystal Mill, Garden of the Gods and with Breckenridge's troll. He's risked encountering a ghost at St. Elmo. He's had a UFO scare. He enjoys sipping on a nice American Pale Ale from Odell Brewing. And he's only 4-years-old.

Oliver can walk only about a mile or two non-consecutively depending on the day, although that drops down to about 100 feet (30.4m) in the snow. When he's ready to stop, he'll lay down on the trail and stare at Smith. She'll scoop him up and put him in either in her hood, jacket pocket or backpack. When he's ready to go again, he'll squirm around, crawl over Smith's shoulder and start checking things out.

Naturally, unassuming hikers have been surprised to see Oliver on the trail in his harness, mistaking him for a small dog, cat, ermine, wild weasel, prairie dog or rat. Smith explains that he's just your regular black-eyed, white ferret.

Dogs, being a curious bunch, often want to get to know Oliver. But he and Smith came across some aggressive dogs once, so now, whenever one is coming, she'll pick Oliver up to prevent any potential harm.

On car trips, Oliver's luggage typically includes a small cage with a litter box, a hammock, blanket, and a harness. He even has his own little tent for camping trips.

- The Denver Post