New for 2026, the Keystone Montana 3900RK is a floor plan that has to be seen to be believed. In this case, the “RK” stands for “rear kitchen,” which only gives the smallest hint of what this layout has to offer. But as you’ll see in the video above, this Montana lives up to the long legacy of the brand, while somehow finding ways to push it in new directions that are exciting and fun.
Photo Credit: Keystone
Spacious, open, and well-equipped, that rear kitchen feels like something you’d find in a home rather than an RV. It comes with an impressive amount of storage—including a dedicated pantry—not to mention a generous amount of solid surface countertops with matching solid surface backsplashes. A large, single-basin stainless steel sink is perfect for clean-up, although the rig features dishwasher prep if you’d rather let a machine do the work. The model in the video comes with a small wine fridge located adjacent to the large, 20-cubic-foot residential-style refrigerator/freezer combo with a built-in ice maker. A four-burner stove with an oven, a convection microwave, built-in paper towel rack, and a dedicated drawer for storing trash bins round out the space.
Midship, you’ll find the living room, which has an absolutely massive L-shaped sofa that sits opposite an equally massive 65″ smart TV and a fireplace. Nearby, a pull-out dinette with two chairs makes a great gathering point for meals, but transforms into a desk when you need to get work done on the road. Just off the living room is a half-bath that includes a toilet, sink, illuminated mirror, and more storage cabinets. The room also includes washer/dryer prep for added convenience on the road.
Photo Credit: Keystone
Finally, the front of the 3900RK floor plan is dominated by the primary bedroom suite. Here, you’ll discover a king-size bed flanked by two nightstands that sit opposite a dresser, a second TV, and yet another fireplace. Directly adjacent is the full bathroom complete with a toilet, couples sinks, a residential-style shower, and dual medicine cabinets. A linen closet provides yet more storage, but not as much as the walk-in closet that sits behind two closed doors and includes a rechargeable cordless vacuum cleaner.
The Keystone Montana 3900RK measures 43′ 10″ end-to-end, has a GVWR of 19,200 lbs., comfortably sleeps 4-6 people, and is rated for 3-4 season camping, meaning it functions fine in the cold, but not extreme cold. The 2026 edition features the company’s new reinforced frame built to extend the overall life of the fifth-wheel. It also comes with a Curt Helix Pin Box hitch that reduces stress on the frame by as much as 30%. Exterior LED lighting adds a nice touch to the exterior design, while optional solar packages and StarLink prep are also noteworthy additions.
Photo Credit: Keystone
We could go on and on about everything this rig has to offer, but honestly, you should just watch the video. It takes you through just about every aspect of the Montana 3900RK, pointing out lots of valuable features along the way. What you’ll find is that this latest model is stunning inside and out, with just about every creature comfort from home covered while you’re on the road. And when you’re done checking out the video, visit the Keystone website to learn more.
Kraig Becker is a writer in the RV, outdoors, and adventure travel space. Over the course of his career he has contributed to such outlets as Popular Mechanics, Outside Online, Business Insider, TripSavvy, Digital Trends, GearJunkie, The Adventure Blog, and countless others. An avid runner and cyclist, he enjoys camping, hiking, mountain biking, kayaking, and just about any other outdoor activity. His travels have taken him to seven continents and on many amazing adventures.
