01 What makes it unique
The 3123RL is where the Montana luxury line starts. It is a triple-slide rear-living fifth wheel with a kitchen island and a private front bedroom — the classic couples’ layout — carrying the full Montana build (12-inch I-beam z-frame chassis, walkable Alpha TPO roof, the Four-Season Living package, hardwood cabinetry, solid-surface counters and the La-Z-Boy furniture package) at the most accessible point in the range.
Its numbers make it the easiest luxury Montana to tow. RVUSA lists a 2,580-pound dry pin — the lowest of the six profiled plans — against a 3,699-pound payload, and a dealer-listed 12,881-pound dry weight derives a GVWR near 16,580 pounds, lighter than the 18,000-pound rating that the larger plans carry. A single 15,000-BTU Coleman Mach heat-pump air conditioner is standard (a triple-15K package is optional), with a 35,000-BTU furnace, an 18-cubic-foot residential refrigerator on a 2,000-watt inverter and a king bed.
At an MSRP of $116,693 — the entry price of the line — it is the Montana for a buyer who wants the brand’s luxury build and rear-living layout without the length, weight or price of the full-timer plans. The optional Legacy Edition adds Dexter disc brakes, a power-cord reel, a surge protector and a roof-mounted Starlink kit for buyers who want to load it toward four-season, off-grid use.
02 Full specifications
Dimensions
- Exterior length
- 35' 1"
- Exterior width
- 8' 0"
- Exterior height
- 13' 4"
- Interior height
- 7' 0"
Weights
- Dry / unit base weight
- 12,881 lbs
- GVWR (max loaded)
- 16,580 lbs
- Net cargo / payload
- 3,699 lbs
- Dry pin weight
- 2,580 lbs
Capacities
- Fresh water
- 70 gal
- Grey water
- 88 gal
- Black water
- 49 gal
- Refrigerator
- 18 cu ft
Construction
- Frame
- 12" I-beam · z-frame
- Walls
- 2" laminated fiberglass · lauan
- Roof
- Alpha TPO · walkable, 5" rafters
- Underbelly
- Four-Season · heated, 0° tested
Running gear
- Axles
- 2 (tandem)
- Hitch
- Fifth-wheel (in-bed)
- Suspension
- MORryde® CRE3000 · wet bolts
- Cooling
- Coleman Mach 15K · 50A
Galley & bath
- Cooktop
- 3-burner recessed
- Refrigerator
- 18 cu ft
- A/C
- 15K Coleman Mach heat-pump (triple-15K opt)
- Water heater
- Quick-recovery · gas/electric
Sleeping & layout
- Sleeps
- 4
- Slides
- 3
- Hitch type
- Fifth-wheel (in-bed)
- Primary bed
- King
03 The Montana floorplan family
Montana is Keystone's flagship luxury fifth wheel and the best-selling luxury fifth wheel in North America. The line runs to fifteen floorplans for 2026; the six highest-demand layouts are profiled here in full, and the rest — along with the lighter, lower-profile Montana High Country sub-line — are catalogued on the line hub. The 3123RL on this page is highlighted; each other profiled plan links to its own page.
| Floorplan | Nominal | Sleeps | Notable |
|---|---|---|---|
| 3123RL | 35 ft | 4 | Rear-living entry, kitchen island |
| 3100RL | 36 ft | 4 | New-2026 widebody, rear-living couples |
| 3231CK | 37 ft | 4 | Rear living, kitchen island + dual pantries |
| 3531RE | 39 ft | 4 | Rear entertainment, glass-door pantry |
| 3532SP | 39 ft | 4 | Side patio, king bed, theater seating |
| 3795FK | 40 ft | 6 | Front raised kitchen, rear full bath, sleeps 6 |
| 3623EB | 40 ft | 4 | Rear living, bike garage, four slides |
| 3761FL | 41 ft | 6 | Front living, bath-and-a-half, 5 slides |
| 3781RL | 41 ft | 4 | Best-selling rear living, kitchen island |
| 3857BR | 41 ft | 8 | Middle bunkroom + loft, family |
| 3901RK | 42 ft | 4 | Rear kitchen, bath-and-a-half, front master |
| 3915TB | 43 ft | 6 | Two full baths, bunkroom + loft |
| 3941FO | 43 ft | 6 | Front office full-timer, outside kitchen |
Montana is the best-selling luxury fifth wheel in North America and Keystone's flagship towable. The full line runs to fifteen floorplans for 2026, plus the lighter, lower-profile Montana High Country sub-line catalogued separately on the hub. Body specifications (lengths, heights, payload, tanks, refrigerator, sleeping, slides and A/C) are RVUSA-verified against the 2026 structured spec records, each page fp-slug and title checked; pin (hitch) weights are from the same records. Montana publishes a 18,000-pound GVWR across the luxury line; the lighter three-slide 3123RL entry carries a derived 16,580-pound GVWR, and the new widebody 3100RL has its dry weight and GVWR flagged as derived. Real loaded pin weights run higher — always weigh the loaded coach and confirm against your truck's payload and rear-axle ratings.
04 What owners & reviewers report
Lowest pin of the six
A 2,580-lb dry pin and the lightest GVWR of the profiled plans — the easiest luxury Montana to match to a truck.
Full Montana build at entry price
12" z-frame chassis, Alpha TPO roof, Four-Season package and La-Z-Boy furniture — the luxury build at the line’s entry MSRP.
Kitchen island, front bedroom
A rear-living couples’ layout with a galley island and a private front bedroom — the most-shopped configuration.
Legacy Edition for off-grid
Optional package adds disc brakes, cord reel, surge protector and roof Starlink — a meaningful four-season, off-grid upgrade.
05 How it compares
The new widebody rear-living hero — five inches more interior width, triple A/C and a heavier chassis at a higher price.
A front-living, bath-and-a-half, five-slide plan — much more living space and a second half bath for full-timers.
Keystone’s mid rear-living fifth wheel — lighter and cheaper, a half-ton-friendlier step below Montana.