2026 Forest River Campsite Ultra21DF

The Campsite Ultra 21DF has 2,107 lbs of cargo capacity between 5,688 lbs dry and its 7,795 lbs GVWR, 27% of that rating; filling its 52-gallon fresh tank at 8.3 lb a gallon uses 432 lbs of it (how to read trailer weights).

Tongue weight is 795 lbs, 14% of the dry weight as published; it rises as the trailer is loaded and counts against the tow vehicle’s tongue-weight and payload limits (tongue weight by size).

Off hookups: 66 gallons of grey and black capacity against 52 gallons of fresh water, so fresh water runs out first (tank sizes by length).

Against the rest of the Campsite Ultra roster this is the 2nd of 6 floorplans by dry weight, in a line that runs from 5,158 lbs to 6,923 lbs. It sits in the lighter third of the line.

Plan the tow on loaded weight, not the 5,688 lbs dry figure: half the published cargo capacity brings this plan to about 6,742 lbs, and the published GVWR of 7,795 lbs is the limit (how to read trailer weights).

Forest River’s line listing and this floorplan’s own factory page agree on all 4 shared figures. Dry weight plus cargo capacity equals the published GVWR exactly. A missing row means Forest River does not publish that figure (how figures are verified).

Forest River publishes no floorplan description for this plan in the channel this page is built from - only the numeric specification block. Rather than describe a layout from the floorplan code, which would be a guess dressed as a fact, this page carries what the factory publishes and says where it stops. 21DF is a Campsite Ultra designation and this site does not decode it into a layout claim.

How the 21DF differs from the other five Campsite Ultra floorplans. Most distinctive first. How these ranks are worked out.

• Exterior height, 10 ft 6 in: lowest of six; next are the 19KB, 25JT and 26CJL (10 ft 7 in).
• Dry weight, 5,688 lb: second-lightest of six, between the 19KB (5,158 lb) and the 26CJL (6,421 lb).
• Cargo capacity, 2,107 lb: second-largest of six, between the 26TH (1,307 lb) and the 19KB (2,442 lb).
• Cargo capacity as a share of GVWR, 27%: second-largest of six, between the 26TH (16.7%) and the 19KB (32.1%).
• Tongue weight as a share of dry weight, 14%: second-largest of six, between the 26TH (12.6%) and the 26BW (14.2%).
• Length, 25 ft 10 in: second-shortest of six, between the 19KB (22 ft 4 in) and the 25JT (30 ft 1 in).
• GVWR, 7,795 lb: third-highest of six, between the 25JT (7,735 lb) and the 26TH (7,820 lb).
• Tongue weight, 795 lb: third-heaviest of six, between the 25JT (735 lb) and the 26TH (820 lb).
• Black tank, 28 gal: smallest of six, level with the 19KB and 25JT; next are the 26BW and 26CJL (38 gal).

Next to the 19KB, the nearest lighter floorplan by dry weight, the 21DF is 530 lb heavier by dry weight, has a GVWR 195 lb higher, has 335 lb less cargo capacity, has a tongue weight 195 lb heavier, is 3 ft 6 in longer and stands 1 in lower; the two publish the same fresh tank, grey tank and black tank.

Next to the 26CJL, the nearest heavier floorplan by dry weight, the 21DF is 733 lb lighter by dry weight, has a GVWR 121 lb higher, has 854 lb more cargo capacity, has a tongue weight 121 lb heavier, is 6 ft 11 in shorter, stands 1 in lower, has a grey tank 10 gal larger and has a black tank 10 gal smaller; the two publish the same fresh tank.

Campsite Ultra is the tightest roster on this site by loaded rating: GVWR spans just 7,600 to 7,985 lb across all six floorplans, a 385 lb spread. What actually varies is what the trailer spends that rating on. Dry weight runs 5,158 to 6,923 lb and cargo capacity runs 927 to 2,442 lb, so the lightest plan carries more than two and a half times the payload of the heaviest one at almost the same loaded weight. Tongue weight runs 600 to 985 lb. For a buyer, the real decision on this line is how much of the tow vehicle’s rating is left for gear.

A full 52-gallon fresh tank is about 432 lb of water (water counts as cargo: 49 CFR 571.110 S9.3.2), 20% of the 21DF’s 2,107 lb cargo capacity, leaving 1,675 lb. Across 6 Campsite Ultra floorplans the water share runs 18% to 47%, and 4 give up more than this one. Nearest on that share: Campsite Ultra 19KB at 18% and Campsite Ultra 26TH at 33%. Your own unit’s figure is on the label inside its entry door (49 CFR 571.110 S9.3.3).