Mammoth Overland’s ‘Wooly’ Designed for Subzero Temperatures

Washington-based Mammoth Overland revealed its WLY, also known as “Wooly,” an all-aluminum off-road trailer designed for winter-sport activities like skiing, snowboard, snowshoeing and snowmobiling, keeping campers comfortable down to temperatures of -20 F (or -28 C).

In order to keep the cabin as warm as possible, Mammoth Overland’s engineers centered WLY’s design around Truma’s VarioHeat 11,500-Btu/hour heater. The VarioHeat is powerful enough to heat a 600-square-foot home and operate up to elevations as high as 8,694 feet above sea level.

WLY’s floor has an R25 insulation rating, while the walls and ceiling are R12. For reference, most trailers are insulated from RO to R5. Designers lined the interior walls, surrounding the standard heated king-size mattress, with wool. More than a cheeky nod to the trailer’s codename, wool serves several key functions. It’s an excellent natural fiber insulator, even when wet. It’s also hypoallergenic and fire resistant — a lesson learned from Mammoth Overland’s parent company, Vashon Aircraft. It’s not just the interior that stays warm; the 21-gallon onboard water tank and lines are heated, too, and stay liquid down to 20 degrees below zero.

“Winters in the Pacific Northwest are beautiful and majestic, especially in the mountains. I wanted to create a trailer that allows folks the ability to explore during winter for more than just the day,” said Mammoth Overland President Scott Taylor. “With Wooly, our engineers exceeded my wildest dreams. During testing, we were able to maintain 85 degrees inside the trailer, even with the kitchen and both doors wide open, with a 27-degree outside temperature. WLY is a dream come true for four-season campers.”

Power comes from four sources: shore power, vehicle towing power, two onboard 100-watt solar panels and a WEN 4,000-watt generator. These power sources feed 800-Amp-hour lithium battery pack from Renogy. WLY isn’t just for winter months, though. Its insulation works both ways; it keeps the interior cool during the summer, too, aiding the standard Dometic RTX 2000 air conditioner. This makes WLY ideal for both snow and surf seasons.

Like its relatives, the HV and ELE trailers, WLY’s kitchen remains outside. However, given its design intent, Mammoth Overland engineers developed an annex that deploys over the rear hatch that contains the kitchen. WLY also boasts a 23ZERO Bushman awning room, so campers can change out of snow gear before entering the trailer. WLY’s roof includes a full-length, molle-panel observation deck and roof rack, which is fitted with MAXTRAX MKIl recovery boards, aggressive Krazy Beaver shovel, ice axe, snowshoes, four ski holders and RotopaX for additional fuel or water storage.

Snow is WLY’s intended trail surface. As such, the trailer’s bronze Method Race Wheels MR318 alloy rims are wrapped in Toyo Open Country A/T Ill tires with 3PMS rating for surefooted grip in snow. Should the trailer — or its tow rig – get stuck, WLY features nine recovery points — five more than standard HV model — rated to 20,000 pounds each.

The fully loaded Mammoth Overland WLY trailer is priced at $56,900. Like all Mammoth Overland trailers, WLY is built to order. Mammoth Overland is taking deposits for WLY now. Deliveries are scheduled to begin in the first quarter of 2025.

Learn more about the WLY on Mammoth Overland’s website.