2026 Forest River Sandpiper3800RK

The 3800RK is Sandpiper’s cook’s plan, and the longest coach in the line. The “RK” marks a residential rear kitchen spread across the back wall — a stainless package, the standard 16-cubic-foot 12-volt refrigerator, abundant counter space and a 30-inch over-the-range microwave — with theater seating, a king front master and washer and dryer as standard (one of only two Sandpiper plans with the laundry included). Four slide-outs open the main level. At 44 feet 1 inch it is the longest coach in the line. It rides the full Sandpiper build: a cambered powder-coated frame, a single tandem 7,000-pound axle rating, an automatic electric level-up system and 200-watt solar.

Forest River lists a published 15,500-pound GVWR against the 12,849-pound dry weight, which leaves a 2,651-pound payload and a 2,405-pound dry pin, on tandem 7,000-pound axles. Two 15,000-BTU air conditioners (prepped for a third), a 60,000-BTU tankless water heater, a 40,000-BTU furnace, heated holding tanks, an 84-inch ceiling and a 50-inch smart television are standard, under dual 13-foot and 16-foot awnings.

For a couple who cooks and wants a residential rear galley, theater seating, a king master and standard laundry in a full-size fifth wheel a tier below the luxury lines — and who tows with a properly rated three-quarter-ton or larger truck — the 3800RK is the cook’s plan.

Sandpiper is Forest River's premium-mainstream full-size fifth wheel — a step below the Cedar Creek and Riverstone luxury lines and a cross-shop against Grand Design's Reflection and Keystone's Cougar. The 2026 retail fifth-wheel line runs to seven floorplans, and all seven are profiled here in full. The 3800RK on this page is highlighted; each other plan links to its own page.

A full 50-gallon fresh tank is about 417 lb of water (water counts as cargo: 49 CFR 571.120 S10.4.2), 16% of the 3800RK’s 2,651 lb cargo capacity, leaving 2,234 lb (558 lb per rated berth). Across 7 Sandpiper floorplans the water share runs 14% to 17%, and 2 give up more than this one. Nearest on that share: Sandpiper 3900HBLR at 15% and Sandpiper 4002FB at 16%. Your own unit’s figure is on the label inside its entry door (49 CFR 571.120 S10.4.3).

Closest sibling: the Sandpiper 4003MB, nearest on the published figures. It differs on 5 of the 9 fields both publish (this plan first): length 44 ft 1 in vs 42 ft 9 in; sleeps 4 vs 8; dry weight 12,849 lb vs 12,609 lb; cargo capacity 2,651 lb vs 2,891 lb; dry hitch weight 2,405 lb vs 2,010 lb. They match on GVWR, fresh tank, grey tank and black tank.

Either side of it by GVWR: Sandpiper 3710HBFB matches it at 15,500 lb GVWR; Sandpiper 4002FB matches it at 15,500 lb GVWR.

All 7 Sandpiper floorplans: Sandpiper line hub.

Against the 3800RK: the Sierra 3710HBFB is 1 ft shorter; the Wildcat 37BEST is 2 lb lighter and sleeps 6 more; the Model Z 3100 is 5 lb lighter and 9 ft shorter and sleeps 3 more.

18 of the 18 fields this catalogue tracks are published for the 3800RK. Not published: tire size (a description is published, a size is not).

Sourcing rules: methodology.