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FLOOR-PLAN RECORD · 2027

Montana 3900RK

The longest Montana and the only one listed for up to 6. The kitchen takes the rear wall, a bar with wine fridge sits in the door-side slide, and the front holds a king bedroom with a two-sink bath and a master wardrobe.

Source checked
Montana 3900RK scale drawing: 43 ft 10 in long, 13 ft 4 in tall Side elevation drawn to scale from the published exterior length of 43 ft 10 in and exterior height of 13 ft 4 in. The outline is a generic fifth-wheel shape, not a profile of this unit. Roof sits 2 in under a 13 ft 6 in limit. Overall length is 3 ft 10 in longer than a 40 ft pad. 13 FT 6 IN CLEARANCE 13 ft 4 in 43 ft 10 in overall 40 FT PAD Roof: 2 in under a 13 ft 6 in limit Length: 3 ft 10 in longer than a 40 ft pad SCALE DRAWING FROM PUBLISHED DIMENSIONS

Drawn to scale from the published 43 ft 10 in length and 13 ft 4 in height, on a generic outline: 2 in under a 13 ft 6 in roof limit and 3 ft 10 in longer than a 40 ft pad.

Montana 3900RK: last on length, first on tanks

Three Montanas share this 2027 lineup. The 3900RK tops it on sleeping and holding-tank capacity and finishes last on cargo capacity.

Length3 of 3, longest43 ft 10 in, 3 ft 10 in past a 40 ft pad
Dry weight3 of 3, heaviest17,085 lb
Pin share1 of 3 lowest3,405 lb on the pin is 19.9% of dry weight; the lighter 3800FL publishes 85 lb more
Sleeping capacity1 of 3Up to 6; the other two list 4
Holding tanks327 gal total77 gal fresh, 150 gal gray, 100 gal black; the only 150 gal gray tank in the family
Cargo carrying capacity3 of 32,320 lb, the lowest in the family

The 3900RK's rear kitchen and its 2,320 lb of cargo

Keystone's tagline starts with "Rear Kitchen" and ends with "Master Suite". On the drawing the sink sits under the rear window with cabinets on both sides, the range and microwave run along the road side, and a peninsula with a pull-out trash can and dishwasher prep closes the kitchen off from the living room. The 20 cu ft 12-volt refrigerator with ice maker, a pantry, and a bar with wine fridge line the door-side slide next to a desk with pull-out dinette. Across from them an L-shaped sofa with a recliner section faces an entertainment center with fireplace and TV.

That is the tradeoff to weigh. A rear kitchen concentrates appliances, pantry stock, and dishes behind the axles, and the 3900RK has the least cargo capacity in the lineup: 2,320 lb, which is 1,650 lb less than the 3100RL and 420 lb less than the 3800FL. It also has the most tank capacity to fill. A buyer drawn to six sleeping places and a 150 gal gray tank should plan the load against the smallest cargo figure in the family.

Forward of the entry steps, a separate room holds a toilet and the washer and dryer prep. The front bedroom has a king bed and a dresser with fireplace and TV, and the front bath adds a shower, linen closet, two sinks with medicine cabinets, a jewelry station, and a master wardrobe.

Keystone's 2027 Montana 3900RK page and drawing →

Walk the 3900RK from the rear sink to the master wardrobe

  1. Stand at the rear sink with every slide closed and reach for the refrigerator. It rides in the door-side slide with the pantry and the wine-fridge bar, so this is how the kitchen works at a fuel stop.
  2. Ask the dealer which piece of furniture provides the extra sleeping places and open it. The drawing shows one king bed while Keystone lists sleeping capacity at 6, and the living room holds the L-shaped sofa with its recliner section.
  3. Open the mid-ship room with the toilet and washer and dryer prep. It is the only laundry prep on the drawing, and appliances installed there come out of a 2,320 lb cargo figure that is already the family's lowest.
  4. In the front bath, check that the two medicine-cabinet sinks, the shower, and the path to the master wardrobe and jewelry station all work with the bedroom slide closed.

Keystone's table for the 3900RK

Length43 ft 10 in
Dry weight17,085 lb
Hitch / pin weight3,405 lb
Sleeping capacityUp to 6
Slides4
Fresh water77 gal
Gray water150 gal
Black water100 gal
Exterior height160 in with A/C
Cargo carrying capacity2,320 lb

Shorter Montanas for 3900RK shoppers who want more cargo

Both alternatives give up sleeping and tank capacity and gain cargo capacity. Figures are computed from the published records.

Front living, almost the same lengthMontana 3800FL

1 ft 3 in shorter and 335 lb lighter, with 85 lb more on the pin at 3,490 lb. It sleeps 4, carries a 100 gal gray tank instead of 150 gal, and has 420 lb more cargo capacity. The living room moves to the front and the bedroom to the rear.

Open record →The short rear-living planMontana 3100RL

7 ft 11 in shorter, 2,055 lb lighter, and 405 lb lighter on the pin. It fits a 40-foot pad, sleeps 4, and has 1,650 lb more cargo capacity, with tanks totalling 227 gal and one bath on the drawing.

Open record →
View every Montana floor plan →
Sources and model year

3900RK source dates and the 160 in roof figure

Length, weights, cargo capacity, tank sizes, sleeping capacity, and exterior height come from Keystone's 2027 Montana 3900RK page, checked on 2026-08-15. On 2026-09-26 the same page, its tagline, and its 2027 drawing were read again for the layout, and the specification table matched.

Keystone labels the published 13 ft 4 in exterior height without separating the A/C. With a main unit and smaller second and third units on the feature list, the number to trust is a tape measure on the unit; the published figure sits 2 in under 13 ft 6 in.