“She crawls in the sleeping bag and cuddles up, that extra heat is always nice,” Craig Armstrong says of his furry travel buddy

By Kelli Bender
June 15, 2015 09:40 PM

Faster than a tumbleweed, more powerful than an indoor cat, able to leap boulders in a single bound. The face of feline domesticity is now the Kitty of Climbing: Millie!

Millie doesn’t come equipped with superpowers, but she has uncovered an impressive skill with the help of her owner Craig Armstrong. Located in Utah, this daring black cat spends most of her weekends scaling rock walls and exploring nature’s wonders.

Last year, Armstrong, an avid climber who was used to seeing dogs on his trips, decided to see what would happen if Millie had a chance to explore the great outdoors, a.k.a the world’s largest litter box.

The cat took to the trails instantly, and she and Armstrong have been pawing their way through canyons and deserts ever since, documenting all of their adventures on Instagram.

Armstrong talked to PEOPLE about how Millie became his backpacking buddy and tips on how to turn your own cat into an explorer.

Tell us about Millie. How did the two of you become a pair?

I was living with a girlfriend at the time. I thought my life was stable enough to finally introduce a pet into our home. So we visited a shelter in Park City, Utah, where I work, called Furburbia one day. We found Millie in a little cage, took her into a quiet room and she climbed right up onto my shoulders. We left with Millie about one minute later; we knew she was going home with us right away.

When and how did you start bringing Millie on climbing trips?

I think it was October. I was going on a lot of climbing trips at the time, almost every weekend. Utah affords amazing climbing almost year-round in either desert or mountain climates, depending on where the weather is best, so I just took Millie with me one day.

People bring their dogs all the time, so it was totally normal for me to bring my pet, which just happened to be a cat. I was going out for a day of bouldering at a place called Joe’s Valley. It was a lot of fun. I loved getting her outside, out of the house, to explore somewhere pretty, and she got on top of a lot of rocks.

Did you have to train her for the trips?

I don’t know if I can honestly say Millie is trained at all. She’s very independent and kind of does what she wants – very cat of her. I tried for sure. A lot.

First, as a kitty, I took her to a little island in a pond at Liberty Park, a small local park in Salt Lake City. All I had to do was guard the bridge and she couldn’t really run away; a safe introduction to the outdoors. I would also take her on drives all the time. Wherever I was going, I’d just bring her with me, hoping she’d get used to being in the truck and it would help on long trips.

I’d take her to a bigger island in the Great Salt Lake called Stansbury Island. It has these huge hills and no brush, so as I’d hike away, she wouldn’t want to be left behind and she’d just follow me up the hills. From the top I’d run back down to my truck and she’d run chasing after me – super cute. This got her used to following me around, which is helpful. I would also call her up onto my shoulders every morning and give her a treat.

If others want to bring their cat climbing, how should they go about starting?

Don’t. Haha. It’s hard. A dog, you can just ignore them, they run around, have fun and come back. No big deal. A cat, you have to watch them at all times. A coyote, fox, owl, eagle, any number of things could kill or injure them. I love getting her outside, but it’s up to me to keep her safe too.

In the beginning, I’d take her on my climbing trips and realized it wasn’t that fun for her while I was climbing. Fun for her is exploring around. So after a few trips, I started taking her on trips with specific objectives just for her. I wanted to see what level she could climb at, so I started doing long slabby routes (not real steep). I wear my harness and attach her to it so she’s on belay and safe if she falls.

The normal routine is we have an objective day one – a climb, a slot canyon, etc. – but that’s my agenda, not hers. So day one we attempt an objective, day two I let her wander the desert freely to explore and I just follow her around to keep her safe. All in all, though, the trips are for her – and for me to have fun with her – and not so much for me to try to climb my hardest. So if you want to take your cat into nature, be ready to put your own agenda away. Be ready to move at a much slower pace, experience nature from a new perspective, and have a lot of patience. Be wary of forcing them too much. Go slow. Give them time to rest, catch shade and follow their own paths too.

Who is the better climber, you or Millie?

Millie is an elite athlete, I can only dream of having the capabilities that little creature contains.

What is the best part about having your cat along on the trips?

The camping at night is fun. She crawls in the sleeping bag and cuddles up, that extra heat is always nice. The times just following her around, letting her explore, are probably the best. You just see things you would normally walk right by, so many flowers, lizards, insects and tracks. You really just experience and explore nature at a slower pace from new angles, and it’s always a good time.

Where is your favorite place that you two have traveled together?

She’s been a lot of places in Utah and Idaho. Hands down, the Southern San Rafael Swell is my favorite. It’s a perfect catting desert and absolutely gorgeous. Specifically the Eastern Reef in the Southern Swell, it’s amazing there. Vistas, canyons, sandstone climbs and amazing desert. I love that place.

Have you met others that bring their cats along on climbs?

Yes, a longtime climbing partner, Zac, is my regular catting partner too. We’ve been on countless trips together, done a lot of summits and slot canyons together. He and his cat, Kenneth, join Millie and [me] on trips all the time.

What is a usual climb like for the two of you?

The hardest part is often the approach. Some climbs have a long approach to the base of the rock. On a normal climb for myself, we hike in pretty quickly. With Millie I go much slower. So a one-hour approach could take two or three hours with her.

Once we get on the rock, though, it’s super fun. Sometimes, Millie goes real fast and I do my best to keep up. Other times she wants to catch shade in a cave and rest, so we just chill. At the end of the day, you realize a few hours have gone by and you haven’t thought about anything else but what’s happening at the time … it’s just kid-like fun. It’s ridiculous, that’s for sure, a dude free soloing moderate routes with a cat on belay, but it doesn’t matter – it’s just super fun.