Rear window, loft, desk, bunk beds, bunkhouse
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2026 Forest River Sierra 4003MB
NewStock #TJ054707
Listing price
2026 Sierra 4003MB
Other floor plans with a similar body style, feature mix, and price range, prioritizing other manufacturers and brands.
Length
42 ft 9 in
Dry weight
12,609 lbs
Sleeps
8
Slideouts
4
What sets the 4003MB apart from most bunkhouse fifth wheels is its rear living area anchored by a rear window, putting the couch and TV at the scenic end of the rig while bunk beds and a loft stay tucked in the middle. The front bedroom earns its keep with a King bed, east/west orientation, and a washer/dryer prep. Details that lean hard into full-time or extended-trip living. A kitchen island with solid surface countertops, a farmhouse sink, and a hidden pantry give the cook's space a residential feel, and the outdoor kitchen means meal prep doesn't have to stay inside. Forest River's Sierra line backs it all up with 7,000 lb. axles with ABS, four-point electric leveling, and a 200W solar panel already on the roof.
Many factors play into a unit's listing price and what you should pay. This guide provides a ballpark estimate, but it does not factor in your exact scenario or how different listings are equipped.
There may be room for price negotiation.
Unlock pricing insights with RV Envy Pro →$59,900 – $69,995
This unit has been on the lot longer than 120 days.
When was this unit listed?This unit ranks near the lowest priced for new units in this model year.
From the dealer's listing
Gather in the rear living room, then retreat to your own space when the day is done. This new 2026 Forest River Sierra 4003MB combines a middle room with seating and a work surface, an upper sleeping area and a separate front bedroom.
The rear sofa and paired lounge seats face a fitted TV and fireplace. A kitchen island, refrigerator, microwave and range make shared meals part of the trip, with a dining table nearby for sitting down together.
The bathroom includes a shower, toilet and sink, and storage throughout gives you places for the essentials. Come explore this particular Sierra and picture your crew here. Call Colman’s RV at 217-793-7300 and ask about stock TJ054707.
Colman's RV
Springfield, IL
Sells faster than 100% of Illinois RV dealers
Compared with 9 dealers in Illinois
Other listings for this floor plan, ranked by condition, model year, distance, price, and listing quality.
The listing price on this unit has changed 3 times.
