Used 2021 Keystone RV Cougar 366RDS Fifth Wheel
Designed with a true rear den layout, this fifth wheel creates distinct living zones so evenings feel relaxed, mornings feel organized, and extended stays feel like home.
Used 2021 Keystone RV Cougar 366RDS Fifth Wheel
If full-time RV living is the goal, the Used 2021 Keystone Cougar 366RDS delivers the space, separation, and residential comfort that make the lifestyle sustainable and exciting. Designed with a true rear den layout, this fifth wheel creates distinct living zones so evenings feel relaxed, mornings feel organized, and extended stays feel like home.
Imagine stepping into your own private living room after a day exploring state parks or settling into a long-term destination. With opposing slides, dual tri-fold sofas, and theater seating facing a large entertainment center, this is a fifth wheel built for comfort-driven travel.
Highlights and Key Features
• Rear separate living room floorplan
• Decorative ceiling arch for elevated interior design
• Two opposing tri-fold sofas for guest sleeping
• Theater seating with cupholders
• 50" LED HDTV and fireplace
• Front private bedroom with queen bed slide
• Optional king bed upgrade
• Dresser and full-height wardrobe
• Large kitchen pantry
• 12 cu. ft. refrigerator with optional 16 cu. ft. upgrade
• Booth dinette or optional free-standing dinette
• 20' power awning
• Accessory hitch for added towing versatility
• MaxTurn technology for improved maneuverability
• Electric four-point auto leveling system
• Heavy-duty axles with never-adjust brakes
• Road Armor™ shock absorbing equalizer
• Climate Guard protection package
• 12V electric heat pads on holding tanks
• 5/8" one-piece DynaSpan® flooring
The rear den is the heart of this 366RDS. Whether hosting grandkids for the weekend or enjoying a quiet movie night, the dual tri-fold sofas expand sleeping capacity while maintaining a cozy residential feel. The fireplace adds warmth and ambiance, turning chilly evenings into comfortable retreats.
The separate kitchen ensures the cook stays connected without feeling crowded. A large pantry provides storage for extended trips, and the generous refrigerator options allow you to stock up for weeks at a time. The choice between booth or free-standing dinette gives flexibility based on your preferred dining style.
Up front, the private bedroom creates a true master suite experience. With a slide-out queen bed (or optional king), full-height wardrobe, and dresser storage, you’ll have the space needed for full-time living.
Outside, the 20-foot power awning sets the stage for evenings under the stars. The accessory hitch provides additional towing capability for bikes, small trailers, or gear—ideal for adventure-focused travelers.
Keystone’s MaxTurn technology enhances turning radius, making campground navigation smoother. The electric four-point auto leveling system simplifies setup, while heavy-duty axles and Road Armor equalization provide a stable, confident tow. With Climate Guard protection and heated holding tanks, this Cougar is engineered for extended-season camping.
Why Buy This RV
The 2021 Cougar 366RDS is ideal for buyers seeking:
• A true full-time capable fifth wheel
• Separate living and kitchen spaces
• Guest-ready sleeping arrangements
• Four-season camping capability
• High-end residential design features
• Enhanced maneuverability and towing stability
This floorplan offers the breathing room and comfort needed for long-term stays without sacrificing mobility or performance.
Why Buy From Campers Inn RV
When you purchase from Campers Inn RV, you gain the support of a dealership committed to your RV journey.
• Knowledgeable staff experienced with full-time fifth wheels
• Detailed pre-delivery inspections
• Flexible financing solutions
• Service and parts support after the sale
• A customer-first approach focused on long-term satisfaction
Campers Inn RV helps ensure your investment in the RV lifestyle is backed by expertise and service you can trust.
If you're ready to transition from weekend camping to full-time adventure, the Used 2021 Keystone Cougar 366RDS is built to deliver residential comfort wherever the road leads.
Anne was an excellent salesperson. She took her time to show us and help us over several months. Always gracious and considerate until we made a decision. We got a fair trade and a great deal.
Much in contrast to an unnamed out of town place where we were under intense pressure to buy the moment we stepped inside.
The rest of the staff were equally helpful. Financing was easy and straightforward. - Joe
You Save: $5,205
Sale Price: $32,995
Stock# 106317B
| Sleeps | 7 |
| Slides | 4 |
| Length | 39 ft 4 in |
| Ext Height | 12 ft 11 in |
| Hitch Weight | 2400 lbs |
| Dry Weight | 11333 lbs |
| Cargo Capacity | 2667 lbs |
| Fresh Water Capacity | 81 gals |
| Grey Water Capacity | 76 gals |
| Black Water Capacity | 38 gals |
| Tire Size | ST235/80R16E |
| Furnace BTU | 35000 btu |
| Available Beds | Queen |
| Refrigerator Type | Gas/Electric |
| Refrigerator Size | 12 cu ft |
| Cooktop Burners | 3 |
| Number of Awnings | 1 |
| LP Tank Capacity | 30 lbs |
| Water Heater Capacity | 6 gal |
| Water Heater Type | Rapid Recovery Gas/Electric |
| AC BTU | 15000 btu |
| TV Info | LR LED HDTV |
| Awning Info | 20' Power |
| Axle Count | 2 |
| Washer/Dryer Available | Yes |
| Number of LP Tanks | 2 |
| Shower Type | Shower w/Seat |
| Electrical Service | 50 amp |
| VIN | 4YDF36624M2505446 |
Cougar 366RDS Reviews
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