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Keystone Cougar 357UMR

Fifth wheelbuilt 2021–22Mixed build tierFindable on the used market
WHAT ONE COSTS
$53,800est. used (2022, 4 yr old)

Sticker was $89,693 in 2022. Out of production since 2022, so the used market is the only way to buy one. Estimate assumes a 2022 unit.

WHAT IT WEIGHS BEHIND YOUR TRUCK
~12,722 lbestimated as towed, for 2 people

dry weight 11,246 lb + fresh water (81 gal, full) 676 lb + propane + battery 200 lb + gear for 2 600 lb. Brochure dry weight omits water, propane, batteries and your gear; this estimate doesn't.

You want a tow rating around14,140 lb (10% margin)
GVWR (the sticker maximum)13,700 lb
Tongue weight, loaded~2,393 lb (19%)
Cargo capacity2,885 lb
WHICH TOW VEHICLES IT FITS: 19 OF 95

Judged the way the app judges: estimated loaded weight against each vehicle's rating less a 10% margin, per model year, because the 357UMR's published weights held steady. Fifth wheels also need a pickup bed and are held to the fifth-wheel rating where published.

VEHICLETOW RATINGVERDICT
Chevrolet Silverado / GMC Sierra 2500HD (Duramax, max tow) '24-2622,500 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 2500HD (Duramax) '20-2318,510 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 2500HD (Duramax) '11-1918,100 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 3500HD (Duramax DRW, gooseneck) '20-2636,000 lbfits, loaded, with 10% margin
Chevrolet Silverado / GMC Sierra 3500HD (Duramax DRW, gooseneck) '11-1923,300 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 diesel, gooseneck) '20-2222,800 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 diesel, tow pkg) '17-1918,000 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 diesel) '11-1616,600 lbfits, loaded, with 10% margin
Ford F-250 Super Duty (6.7 HO diesel, gooseneck) '23-2623,000 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '17-1932,500 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '20-2237,000 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 diesel DRW, gooseneck) '11-1621,600 lbfits, loaded, with 10% margin
Ford F-350 Super Duty (6.7 HO diesel DRW, gooseneck) '23-2638,000 lbfits, loaded, with 10% margin
Ford F-450 Super Duty (6.7 HO diesel DRW, gooseneck) '23-2640,000 lbfits, loaded, with 10% margin
Ram 2500 (6.7 Cummins HO) '19-2620,000 lbfits, loaded, with 10% margin
Ram 2500 (6.7 Cummins) '11-1817,980 lbfits, loaded, with 10% margin
Ram 3500 (6.7 Cummins DRW, gooseneck) '13-1831,210 lbfits, loaded, with 10% margin
Ram 3500 (6.7 Cummins HO DRW, gooseneck) '25-2636,610 lbfits, loaded, with 10% margin
Ram 3500 (6.7 Cummins HO DRW, gooseneck) '19-2437,090 lbfits, loaded, with 10% margin
The 76it doesn't fit

These verdicts assume 2 people aboard with typical gear. See the margin for your truck and your crew →

THE SPECS
Length39.3 ft
GVWR13,700 lb
Dry weight11,246 lb
Dry tongue weight2,115 lb
Cargo capacity2,885 lb
Sleeps6
Slide-outs3
Axles2
Fresh water81 gal
Grey water76 gal
Black water76 gal
Awning13 ft

A missing row means the maker never published that figure: unknown, not zero.

WHERE PEOPLE SLEEP
  • 1× rear bedroom king(Permanent)70×80
  • 1× tri-fold sleeper sofa(Convertible)—
  • 1× booth dinette converts to bed(Convertible)—
HOW IT'S BUILT: 4/5
WallsLaminated fiberglass
FrameAluminum
RoofWalk-on
UnderbellyEnclosed

Keystone (Mixed tier): Keystone's mid-tier fifth wheel — decent laminated build and huge volume, but Keystone-grade QC keeps it out of the top tier.

YEAR BY YEAR: WHAT CHANGED
  • 2021Introduced
  • 2022Dropped after two model years
FINDING ONE

Findable: a few listed nationwide most weeks. Why: Keystone is a volume manufacturer; only 2 model years. Estimated from build volume and production span, not a count of live listings.

OUR TAKE

Two-year-only ultimate-master-retreat plan with an oversized rear bedroom suite.

OTHER COUGAR FLOORPLANS
23MLE · 10,075 lb · sleeps 623MLS · 10,000 lb · sleeps 624RDS · 10,000 lb · sleeps 625RES · 10,000 lb · sleeps 6260MLE · 12,000 lb · sleeps 426RES · 10,300 lb · sleeps 426RKE · 11,000 lb · sleeps 62700BH · 9,900 lb · sleeps 1027SGS · 10,290 lb · sleeps 428RLI · 11,000 lb · sleeps 6290RLS · 12,200 lb · sleeps 629MBD · 11,500 lb · sleeps 1029MBS · 11,000 lb · sleeps 929RKS · 10,400 lb · sleeps 6the whole line →
Find one for sale

Live listings for the 357UMR on the big marketplaces. Each search opens pre-filled with this exact floorplan:

RV Trader ↗Camping World ↗FB Marketplace ↗Google ↗

Inventory varies by site and day. Slim pickings? search the whole Cougar line ↗

Is the 357UMR your #1, or just a spec sheet?

These are the facts. Whether it beats the other six thousand rigs for you depends on what you care about. Set your priorities as sliders, switch on your hard limits, and watch the whole market re-rank around them. Every exclusion explained, every margin shown.

See where it ranks for you →

Data compiled from dealer and aggregator listings, retrieved 2026-07.