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Keystone Montana Mountaineer 310RET

Fifth wheelbuilt 2014–15Mixed build tierFindable on the used market
WHAT ONE COSTS
$27,800est. used (2015, 11 yr old; from 15 priced floorplans of this line)
WHAT IT WEIGHS BEHIND YOUR TRUCK
~12,480 lbestimated as towed, for 2 people

dry weight 11,130 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 around13,870 lb (10% margin)
GVWR (the sticker maximum)14,295 lb
Tongue weight, loaded~2,573 lb (21%)
Cargo capacity3,165 lb
WHICH TOW VEHICLES IT FITS: 20 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 310RET'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-150 (3.5 EcoBoost, max tow) '21-2314,000 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 75it doesn't fit

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

THE SPECS
Length34.8 ft
Height (incl. A/C)12.8 ft
Width8.0 ft
GVWR14,295 lb
Dry weight11,130 lb
Dry tongue weight2,295 lb
Cargo capacity3,165 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
  • 1× Front bedroom queen(Permanent)—
  • 1× Bench dinette converts(Convertible)—
  • 1× Sofa converts(Convertible)—
HOW IT'S BUILT: 3/5
WallsLaminated fiberglass
FrameAluminum
RoofStandard
UnderbellyEnclosed

Keystone (Mixed tier): Montana

YEAR BY YEAR: WHAT CHANGED
YEARSGVWRDRYMSRP
201414,295 lb11,040 lb—
201514,295 lb11,130 lb—
  • 2014Introduced
  • 2015Shipping weight up to 11,130 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

Rear-entertainment triple-slide from the final two model years.

OTHER MONTANA MOUNTAINEER FLOORPLANS
285RLD · 14,185 lb · sleeps 6290RLT · 14,045 lb · sleeps 6291RLT · 14,295 lb · sleeps 6295RKD · 14,395 lb · sleeps 6298RLS · 12,690 lb · sleeps 6303RLD · 13,960 lb · sleeps 6305RLT · 14,185 lb · sleeps 6307RKD · 14,080 lb · sleeps 6319BHD · 13,880 lb · sleeps 8324RLQ · 14,400 lb · sleeps 6325RLT · 14,140 lb · sleeps 6326RLT · 14,185 lb · sleeps 6327RLT · 14,090 lb · sleeps 6329RLT · 14,035 lb · sleeps 6the whole line →
Find one for sale

Live listings for the 310RET 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 Montana Mountaineer line ↗

Is the 310RET 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.