37MD figures, with its 13 ft 3 1/4 in roof line
The Murphy-bed room is what separates the 37MD
Heartland's current drawing labels the room between the kitchen and the bath in detail: a Murphy bed listed at 60 x 74 with a desk, TV, and shelves, a removable table, a loft above, and a road-side slide holding a 60-inch trifold sofa with a flip-up bunk above. Behind it, the rear living area has a 78-inch hide-a-bed tri-fold sofa across the rear wall, a theater seat and a roll top table in the door-side slide, and a kitchen island with a pull-out cutting board facing a road-side slide with a hidden pantry, shelves, microwave, and residential fridge. Up front is a 72 by 80 inch king bed in its own slide, with a 36 by 48 inch shower in the bath ahead of it. Four slides in all.
The added room costs 6 ft 10 in and 2,590 lb over the 31RL, but only 300 lb of hitch weight. At 2,705 lb the 37MD's pin is 3 of 7 lightest, 265 lb under the shorter 38RE, and as a share of unloaded weight it is the lowest in the family.
What it gives up is margin. GVWR minus unloaded weight is 2,450 lb, 6 of 7; only the 39FL's 2,350 lb is smaller. The 39RK, 5 in longer and rated for 4, leaves 550 lb more. Eight people's food, water, and gear have to fit inside the smaller figure, which Heartland prints as the plan's cargo carrying capacity. The tanks do not grow with the head count either: 75 gal fresh, 87 gal gray, and 50 gal black, 212 gal in all, the same set the 31RL carries for half as many people.
Heartland's current Bighorn 37MD floor plan →37MD against the six other 2026 Bighorns
Four stops through the 37MD, starting at the Murphy bed
- Fold the Murphy bed down and back up. The drawing lists it at 60 x 74 with a desk, TV, and shelves on the same wall, so check what has to be cleared off the desk each night.
- Close the mid room's slide and look at the 60-inch trifold sofa with its flip-up bunk. With the slide in, check that the bunk can still be reached and that the hall to the bath stays clear.
- At the rear, open the 78-inch hide-a-bed sofa and see whether it clears the island and the roll top table, which the 2026 brochure lists with two free-standing and two folding chairs.
- Outside, read the height on the unit. Heartland prints 13 ft 3 1/4 in with the air conditioner, a quarter inch above the 13 ft 3 in of five siblings, leaving 2 3/4 in under 13 ft 6 in.
Three Bighorns measured against the 37MD's eight berths
Differences are arithmetic from Heartland's spec table.
1 ft longer, 460 lb heavier, and 220 lb more on the hitch, with GVWR 750 lb higher and 290 lb more margin. Its tanks swap emphasis: 100 gal black, 50 gal more, and 50 gal gray, 37 gal less.
Open record →Shorter by the length of the mid roomBighorn 31RL6 ft 10 in shorter, 2,590 lb lighter, 300 lb lighter on the hitch, GVWR 2,100 lb lower, and one slide fewer. It sleeps 4 and is the only Bighorn under 40 feet.
Open record →Nearly the same length, far more gray tankBighorn 38RE4 in shorter and 375 lb lighter, with GVWR 105 lb lower but 265 lb more on the hitch. It sleeps 4, puts a TV lift and fireplace on the rear wall in place of the hide-a-bed sofa, and its 137 gal gray tank is 50 gal larger.
Open record →37MD sources and the quarter-inch height
All figures are from the spec table in Heartland's 2026 Bighorn brochure (Rev. 2/26), last checked here on 2026-08-15, including the 13 ft 3 1/4 in exterior height with the air conditioner, the only Bighorn height with a fraction. Room labels come from Heartland's current 2027 Bighorn 37MD drawing, read on 2026-09-26, because the brochure prints this plan too small to read; check the exact 2026 unit against that drawing. The slide count is from RVUSA's 2026 spec guide. Heartland footnotes that some specs at the time of print may include estimates.