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Keystone Montana High Country 377FL

Fifth wheelbuilt 2021– (in production)Mixed build tierCommon on the used market
WHAT ONE COSTS
$108,600MSRP today

Still in production. A used 2023 would run roughly $64,100.

WHAT IT WEIGHS BEHIND YOUR TRUCK
~14,939 lbestimated as towed, for 2 people

dry weight 13,513 lb + fresh water (75 gal, full) 626 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 around16,600 lb (10% margin)
GVWR (the sticker maximum)16,620 lb
Tongue weight, loaded~2,896 lb (19%)
Cargo capacity3,107 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 377FL'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
Length41.9 ft
Height (incl. A/C)13.3 ft
Width8.4 ft
GVWR16,620 lb
Dry weight13,513 lb
Dry tongue weight2,620 lb
Cargo capacity3,107 lb
Sleeps10
Slide-outs4
Axles2
Fresh water75 gal
Grey water78 gal
Black water39 gal
Air conditioning30,000 BTU
Solar (standard)220 W

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

WHERE PEOPLE SLEEP
  • 1× rear private bedroom king(Permanent)72×80
  • 1× overhead loft(Convertible)—
  • 2× front living sofas(Convertible)—
  • 1× dinette(Convertible)—
HOW IT'S BUILT: 4/5
WallsLaminated fiberglass
FrameAluminum
RoofWalk-on
UnderbellyEnclosed

Keystone (Mixed tier): The lighter half of Keystone's Montana family — a 101in wide body with frameless windows, six-point hydraulic auto-levelling, Curt slipper-roll suspension and a Helix pin box, plus a SolarFlex package standard. Good residential feel for the money; Keystone's volume-plant QC is the usual caveat.

YEAR BY YEAR: WHAT CHANGED
  • 2021Earliest year in Keystone's published spec archive
FINDING ONE

Common: usually several for sale within a day’s drive. Why: Keystone is a volume manufacturer; still in production. Estimated from build volume and production span, not a count of live listings.

OUR TAKE

Four-slide front living room with a rear overhead loft; sleeps ten without a bunk room. GVWR derived.

OTHER MONTANA HIGH COUNTRY FLOORPLANS
280CK · 14,300 lb · sleeps 4281CK · 14,250 lb · sleeps 4290RL · 16,255 lb · sleeps 4294RL · 14,300 lb · sleeps 6295RL · 15,300 lb · sleeps 6300RK · 15,700 lb · sleeps 4311RD · 15,600 lb · sleeps 6325RK · 15,985 lb · sleeps 6330RL · 14,260 lb · sleeps 6331RL · 16,580 lb · sleeps 6334BH · 16,000 lb · sleeps 8350BH · 16,000 lb · sleeps 8351BH · 16,655 lb · sleeps 8362RD · 16,000 lb · sleeps 8the whole line →
Find one for sale

Live listings for the 377FL 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 High Country line ↗

Is the 377FL 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.