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Keystone Montana Mountaineer 331RLT

Fifth wheelbuilt 2014–15Mixed build tierFindable on the used market
WHAT ONE COSTS
$29,400est. used (2015, 11 yr old; from 15 priced floorplans of this line)
WHAT IT WEIGHS BEHIND YOUR TRUCK
~12,755 lbestimated as towed, for 2 people

dry weight 11,405 lb + fresh water (66 gal, full) 550 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 around14,175 lb (10% margin)
GVWR (the sticker maximum)14,305 lb
Tongue weight, loaded~2,578 lb (20%)
Cargo capacity2,900 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 331RLT's published weights changed mid-run. 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
Length36.8 ft
Height (incl. A/C)12.8 ft
Width8.0 ft
GVWR14,305 lb
Dry weight11,405 lb
Dry tongue weight2,305 lb
Cargo capacity2,900 lb
Sleeps6
Slide-outs3
Axles2
Fresh water66 gal
Grey water93 gal
Black water50 gal
Awning16 ft

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

WHERE PEOPLE SLEEP
  • Front bedroom queen(Permanent)
  • Bench dinette converts(Convertible)
  • Sofa converts(Convertible)
HOW IT'S BUILT: 3/5
WallsLaminated fiberglass
FrameAluminum
RoofStandard
UnderbellyEnclosed

Keystone (Mixed tier): Montana

YEAR BY YEAR: WHAT CHANGED
YEARSGVWRDRYMSRP
201414,305 lb11,265 lb
201514,305 lb11,405 lb
  • 2014Introduced
  • 2015Shipping weight up to 11,405 lb
  • 2016Line discontinued
FINDING ONE

Findable: a few listed nationwide most weeks. Why: Keystone is a volume manufacturer; only 2 model years; 11 years out of production. Estimated from build volume and production span, not a count of live listings.

OUR TAKE

Largest rear-living plan of the final two years; 2,900 lb of cargo on a 14,305 lb GVWR.

OTHER MONTANA MOUNTAINEER FLOORPLANS
Find one for sale

Live listings for the 331RLT on the big marketplaces. Each search opens pre-filled with this exact floorplan:

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

Is the 331RLT 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.