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Keystone Montana Mountaineer 305RLT

Fifth wheelbuilt 2008–10Mixed build tierFindable on the used market
WHAT ONE COSTS
$18,800est. used (2010, 16 yr old)

Sticker was $47,315 in 2010. Out of production since 2010, so the used market is the only way to buy one. Estimate assumes a 2010 unit.

WHAT IT WEIGHS BEHIND YOUR TRUCK
~11,697 lbestimated as towed, for 2 people

dry weight 10,338 lb + fresh water (67 gal, full) 559 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 around13,000 lb (10% margin)
GVWR (the sticker maximum)14,185 lb
Tongue weight, loaded~2,472 lb (21%)
Cargo capacity3,847 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 305RLT'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-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
Length34.3 ft
Height (incl. A/C)12.8 ft
Width8.0 ft
GVWR14,185 lb
Dry weight10,338 lb
Dry tongue weight2,185 lb
Cargo capacity3,847 lb
Sleeps6
Slide-outs3
Axles2
Fresh water67 gal
Grey water93 gal
Black water50 gal

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

WHERE PEOPLE SLEEP
  • Front bedroom queen(Permanent)
  • 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
  • 2008Introduced at 9,895 lb shipping weight
  • 2009Shipping weight 10,338 lb; 93 gal grey
  • 2011Dropped
FINDING ONE

Findable: a few listed nationwide most weeks. Why: Keystone is a volume manufacturer; 16 years out of production. Estimated from build volume and production span, not a count of live listings.

OUR TAKE

First triple-slide Mountaineer. GVWR derived from shipping weight plus carrying capacity.

OTHER MONTANA MOUNTAINEER FLOORPLANS
Find one for sale

Live listings for the 305RLT 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 305RLT 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.