# Forest River Sierra 4003MB

> Rear window, loft, desk, bunk beds, bunkhouse

4003MB is a fifth wheel floor plan by Sierra (Forest River).

## Specs (2026 model year)

| Spec | Value |
| --- | --- |
| Length | 42 ft 9 in |
| Sleeps | 7 |
| Slide-outs | 4 |
| Dry weight | 12,609 lbs |
| GVWR | 15,500 lbs |

## Model years

2026, 2025, 2024. Year-specific specs: `https://rvenvy.com/fifth-wheel-trailers/forest-river/sierra/4003mb?year={year}`

## Floor plan tags

loft, desk, mid bunk, front bedroom, rear living area

## Inventory

13 units currently for sale priced $62,980 to $75,109: https://rvenvy.com/fifth-wheel-trailers/forest-river/sierra/4003mb/inventory

Floor plan diagram: https://images.rvenvy.com/9833f407d088ecdbc6731eee5bc607eb6e903a77b8f4fcd9bbcc58af3228614c/1024.webp

Canonical page: https://rvenvy.com/fifth-wheel-trailers/forest-river/sierra/4003mb