01 What makes it unique
The 37MD solves the problem long coaches usually ignore: everyone in one room. A dedicated middle den sits between the rear living area and the front bedroom — a second zone for kids, guests, an office or a quiet television — opened by one of the coach’s four slides, and the factory’s eight-berth rating (the highest in the line, shared with the 40DB) follows from it. Outside, two 20-foot awnings run the longest combined shade line in the roster.
The build is the shared platform at nearly full stretch: 12-inch I-beam drop frame, 102-inch wide-body, CoreShield laminated walls, painted front cap, frameless windows, TrussXL truss, limited-lifetime membrane, ThermaShield zero-degree package with the 40,000-BTU furnace, dual 15,000-BTU Whisper Quiet air, tankless water heater, six-point hydraulic auto-level and the mandatory Premium Package with the GE residential suite. The printed 18,100-pound GVWR equals 15,650 dry plus 2,450 cargo exactly, on tandem 8,000-pound axles with 17.5-inch H-rated rubber.
The margins tell the family story honestly: 2,450 pounds of cargo capacity is the second-tightest in the line, and eight occupants’ gear plus a filled 75-gallon fresh tank (about 625 pounds) will spend it — weigh the loaded coach. The 2,705-pound dry pin is one-ton territory outright. Like the rest of the roster, RVUSA’s weight record is the stale early print; the current factory set, brochure-confirmed in June 2026, is used.
02 Full specifications
Dimensions
- Exterior length
- 42' 10"
- Exterior width
- 8' 6"
- Exterior height
- 12' 7"
- Interior height
- 8' 6"
Weights
- Dry / unit base weight
- 15,650 lbs
- GVWR (max loaded)
- 18,100 lbs
- Net cargo / payload (CCC)
- 2,450 lbs
- Dry pin weight
- 2,705 lbs
Capacities
- Fresh water
- 75 gal
- Grey water
- 87 gal
- Black water
- 50 gal
- Refrigerator
- GE 21 cu ft residential
Construction
- Frame
- 12″ steel I-beam · drop frame
- Sidewalls
- CoreShield 2″ laminate · high-gloss gel coat
- Front cap
- Painted fiberglass · clearcoat · LED
- Roof
- TrussXL truss · Alpha membrane (limited lifetime)
Running gear
- Axles (factory)
- 2 x 8000
- Hitch
- Fifth wheel · dry pin 2,705 lb
- Tires
- 215/75R17.5'H'
- LP
- 90 lb total
Galley & systems
- Refrigerator
- GE 21 cu ft residential · 1,800W inverter
- A/C
- 2 × 15,000 BTU Whisper Quiet
- Water heater
- Tankless
- Furnace
- 40,000 BTU
Sleeping & layout
- Sleeps
- Up to 8 (factory)
- Primary bed
- Front bedroom
- Layout
- Middle-den quad-slide — separate mid den between the rear living area and front bedroom, two 20-foot awnings
- Awnings & entries
- 2 · 20′ + 20′ · 1 entry (RVUSA)
Verified specs, drawn to scale
Original graphics built from this floorplan’s own verified figures.
Loaded weight budget
Size, drawn to scale
Holding tanks
Drawn by this site from the verified figures above, never traced from a manufacturer drawing; a graphic is left out where its figure is not published. Full record: dataset.
What it takes to tow this
Built from this floorplan’s verified weights. We publish the trailer side only.
Truck tow ratings are not listed: one model varies by thousands of pounds across engine, axle ratio, cab and package. The loaded range is the 15–25% pin-weight convention for fifth wheels, applied to this plan’s 18,100 lb GVWR, not a measurement of this unit. Hitch class is not used as a rating (SAE J684 covers trailers to 10,000 lb GVWR); read the rating stamped on your hitch.
03 Bighorn floorplan family
Heartland's Bighorn line — the flagship luxury fifth wheel of the relaunched range: seven 2026 floorplans, every one a 102-inch wide-body on a 12-inch steel I-beam drop frame with a painted fiberglass front cap, CoreShield laminated sidewalls in high-gloss gel coat, the ThermaShield zero-degree package with a 40,000-BTU furnace, two 15,000-BTU Whisper Quiet air conditioners, and a mandatory Premium Package that includes six-point hydraulic auto-leveling, a GE 21-cubic-foot residential refrigerator with an 1,800-watt inverter and a GE appliance suite. All seven plans are profiled in depth on the Bighorn hub with verified weights.
| Floorplan | Nominal | Sleeps | Notable |
|---|---|---|---|
| 31RL | 36 ft | 4 | Rear-living entry — shortest, lightest, friendliest pin |
| 36RK | 40 ft | 4 | Rear-kitchen plan — the galley takes the back wall |
| 38RE | 43 ft | 4 | Rear-entertainment quad-slide — most-listed; 137-gal grey |
| 37MD | 43 ft | 8 | Middle-den quad-slide — two living zones |
| 39RK | 43 ft | 4 | Rear U-kitchen, bath-and-a-half — respec’d stretch; best margin |
| 39FL | 44 ft | 4 | Front-living flagship — five slides, heaviest pin |
| 40DB | 44 ft | 8 | Two bedrooms, two full baths — the multi-family flagship |
Every Bighorn is a 102-inch wide-body on the 12-inch I-beam drop frame, and the Premium Package is mandatory — its content (hydraulic auto-level, the GE residential appliance suite with inverter, central vacuum, gel-coat sidewalls) is part of the Base MSRP shown. This is a published-GVWR-clean line: dry plus cargo equals the printed GVWR exactly on all seven plans. RVUSA and the library brochure carry an early-print weight set superseded on five plans — the current factory pages and the June-2026 dealer-network brochure agree exactly and are used throughout (the 39RK was respecified from a 40-foot-4 two-slide draft to the current 43-foot-3 three-slide build, logged). Dealer placards typically run above Base MSRP while negotiated street pricing runs below it. A fifth wheel loads its pin into the truck bed — confirm the pin weight against the tow vehicle's payload placard, not its tow rating.
04 Notes on this floorplan
The den is the plan
A true second living zone amidships — door-separated space the bunk-room formula approximates but does not match for adults.
Eight berths, 2,450 pounds
The line’s top sleep rating against its second-tightest margin — load deliberately and scale the loaded coach.
40 feet of awning
Two 20-footers — the longest combined shade line in the roster.
05 How it compares
The other eight-sleeper — two true bedrooms and two full baths instead of the den, with a 100-gallon black tank.
The entry rear-living plan — 2,590 pounds lighter for couples who do not need the second zone.
The multi-zone luxury field — the 37MD counter is the standard residential suite and the zero-degree ThermaShield package.
06 Loading it for a trip
This floorplan carries its water comfortably. A full 75-gallon fresh tank is roughly 26% of the 2,450-pound cargo capacity, leaving the Bighorn 37MD with a usable gear budget even when you tow full.
| Weight budget | Figure | What it means |
|---|---|---|
| Cargo capacity as published (CCC) | 2,450 lb | Everything you add: gear, water, propane, batteries, food, people’s belongings. |
| Fresh tank filled (75 gal × 8.34 lb) | −626 lb | Water is the heaviest thing most owners add, and it is added first. |
| Cargo budget left with a full fresh tank | 1,824 lb | 26% of this plan’s capacity is spent before a single bag is loaded. |
| Per sleeping position, water aboard | 228 lb | A rough share of what is left across the 8 berths this plan sleeps. |
The published dry pin weight of 2,705 pounds is 17% of this floorplan’s 15,650-pound dry weight. Fifth-wheel pin weight rides in the bed of the truck, so it comes off payload rather than off tow rating — and it rises with the trailer as you load it, not in proportion to what you put over the axles.
Nothing above changes the ceiling. Loaded to its 18,100-pound GVWR the Bighorn 37MD is towing 2,450 pounds more than its 15,650-pound dry figure, and that is the number your vehicle has to be rated for — not the brochure weight.
Tank balance is generous here: 75 gallons of fresh against 87 grey and 50 black, so waste capacity keeps pace with supply and the fresh tank is the constraint that ends a dry stay.
07 Where this floorplan sits
Ranked by GVWR, the Bighorn 37MD sits 5 of 7 in the Bighorn line: 18,100 pounds against a line that runs from 16,000 to 18,850 pounds. That position is the useful thing to know, because the plans immediately either side of it are the real alternatives.
Either side of it in the same line: Bighorn 39FL is 105 pounds lighter at 17,995 lb GVWR; and Bighorn 39RK is 100 pounds heavier at 18,200 lb GVWR.
| Comparable fifth wheels | GVWR (lb) | Dry (lb) | Sleeps | Length |
|---|---|---|---|---|
| Bighorn 37MD | 18,100 | 15,650 | 8 | 42 ft 10 in |
| North Point 377RLBH | 18,100 | 15,560 | 7 | 42 ft 11 in |
| Cedar Creek 375RD | 18,110 | 13,874 | — | 42 ft 6 in |
| Influence 3003RL | 18,000 | 12,500 | 4 | 34 ft 11 in |
| Montana 3100RL | 18,000 | 14,030 | 4 | 35 ft 11 in |
| Paradigm 375RD | 18,000 | 14,771 | 5 | 41 ft 9 in |
| Pinnacle 38FBRK | 18,200 | 15,448 | 4 | 43 ft 10 in |
Against the Bighorn 37MD: the North Point 377RLBH sleeps 1 fewer; the Cedar Creek 375RD is 10 lb heavier; the Influence 3003RL is 100 lb lighter and 8 ft shorter and sleeps 4 fewer. Those are differences in the published numbers only — what they cost, how they are built and how they live are separate questions each of those pages answers on its own terms.
Those are the nearest fifth wheels from other lines by weight — one per line, picked by proximity on that figure and nothing else. They are listed so the same tow vehicle can be checked against real alternatives, not because they are equivalent inside; layout, build and price diverge sharply across that group.
For scale, the Bighorn floorplans profiled here run 13,060 to 16,110 pounds dry and 36 to 44 feet of exterior length across 7 plans. Where a floorplan falls in that spread usually says more about which vehicle can tow it, and which site it fits, than the layout name does.
Every profiled floorplan in this line, with the full weight table, is on the Bighorn line hub.
08 Common questions about the Bighorn 37MD
How much does the Bighorn 37MD weigh?
Its published dry weight is 15,650 lb and its GVWR is 18,100 lb, so 2,450 lb separates the empty trailer from its rated maximum. By GVWR it is the 3rd-heaviest of the 7 Bighorn floorplans profiled here that publish a GVWR (16,000 lb to 18,850 lb). Size the tow vehicle to the 18,100 lb figure, not the dry one.
How much can the Bighorn 37MD carry?
Cargo carrying capacity is 2,450 lb, 14% of the GVWR. Across the 307 fifth wheels on this site that publish both figures, the median share is 19%, so this plan sits 5 points below the median. A full 75-gallon fresh tank is about 626 lb of it (26%), because federal rule counts on-board water as cargo (49 CFR 571.120 S10.4.2). The yellow cargo-capacity label inside your own trailer’s entry door (49 CFR 571.120 S10.4.3) states the figure for that unit as delivered, options included, and it is the one that binds.
What is the pin weight of the Bighorn 37MD?
The published dry pin weight is 2,705 lb, 17% of the dry weight. Across the 386 fifth wheels on this site that publish both figures, the median dry pin share is 19%, so this plan sits 2 points below the median. Loaded, it changes with where the cargo sits, and it is carried by the tow vehicle’s payload, not its tow rating.
What size tow vehicle does the Bighorn 37MD need?
A tow rating of at least 18,100 lb, this floorplan’s GVWR, plus enough payload for the pin load, passengers and cargo. The dry pin weight alone takes 2,705 lb of that payload before anything is loaded. Payload is printed on the tire and loading placard on the tow vehicle’s driver-side door pillar (49 CFR 571.110 S4.3); this site lists no truck ratings because they vary by build.
How many people does the Bighorn 37MD sleep?
It is rated to sleep 8. No other Bighorn floorplan profiled here is rated for more (7 publish a count). Rated positions include convertible furniture.
What are the tank capacities on the Bighorn 37MD?
Fresh 75 gallons, grey 87 gallons, black 50 gallons. The smallest of the three is the black tank, at 50 gallons. Combined waste capacity is 137 gallons.
How long is the Bighorn 37MD?
Exterior length is 42' 10". That makes it the 4th-shortest of the 7 Bighorn floorplans profiled here that publish an exterior length (36 ft 0 in to 43 ft 10 in). Check it against campsite and storage length; the exterior figure includes the tongue or pin box.
Every figure in these answers is read from this page’s verified specification table. Where the manufacturer publishes nothing, the question is not answered rather than estimated.
09 What this page publishes, and what it does not
Named sources publish 16 of the 18 specification fields this catalogue tracks for the Bighorn 37MD (95% complete on the full field set).
Not published for this floorplan: slide count, awning. Those rows are left blank rather than copied from a sibling floorplan.
Sourcing rules: methodology.
11 NHTSA safety record
This floorplan belongs to the Bighorn line, and NHTSA holds 20 recall campaigns and 51 owner complaints against that line. They are separate records and are not added together — a recall is a manufacturer-confirmed defect with a remedy; a complaint is one owner’s account, which NHTSA does not verify.
What to look at on a used one. Across the 51 complaints filed on this line the most-reported components are tires (41%), suspension (14%) and structure (10%). That is where owners of this family have had trouble, so it is where an inspection is worth the time.
Recall coverage is not complete — our harvest of NHTSA’s recall API ran 1,556 queries, of which 0 failed and 242 returned an explicit zero. A line can still be under-reported where NHTSA files a roster under a parent name, or where a match rests on the wording of the recall rather than its model field. Complaints come from the complete bulk file but are unverified and self-selected: a high count tracks how many units a line sold at least as much as how well it was built. Check a specific VIN at NHTSA before you buy. Full tables are on the Bighorn line page.