Bear Adventure Truck Camper is Small Yet Loaded for Off-Grid Camping

There’s no doubt about it. Today’s truck camper is far more capable than they use to be. Indeed, compare a truck camper from the 1990s to a truck camper from today and the differences are mind boggling. Sure, solar power, DC-DC chargers, and lithium batteries have the changed the game completely, but when you factor other advances like composting toilets, diesel heaters, induction cooktops, DC refrigerators, and DC air conditioners, the differences are stark. One example of these advancements is the truck camper built by Bear Adventure Vehicles. This hard-side camper has nearly all of the advancements mentioned previously all within the confines of what can only be classified as a small truck camper. Steve and Kirsten Dunn are the proud owners of one. We were fortunate enough to meet Steve and Kirsten and get a tour of their amazing Bear Adventure rig at the 2025 Truck Camper Adventure Quartzsite Rally. To learn more about their rig and where they’ve taken it so far, they were kind enough to answer several questions.

Thanks, guys, for taking the time to talk with us. Can you tell us a little bit about yourself?

Steve and Kirsten: We’re Steve and Kirsten Dunn. We met in college at Northern Arizona University in Flagstaff, AZ, 41 years ago. With a shared passion for the outdoors and a desire to get off the beaten path, we’ve been traveling in our truck camper from the southern tip of Baja to the northernmost point of the Dempster Highway at Tuktoyaktuk, where the Arctic Ocean meets the land. Over the years, we’ve lived, worked, and camped across the US, from Arizona to Virginia, and California to South Carolina. Along the way, we raised our family and enjoyed countless camping adventures in various tents, trailers, camper vans, and truck campers. After successfully raising and launching our two kids (and Steve’s retirement from the Navy in 2023), we decided to extend our camping trips, making them longer and more immersive. Knowing that this required a different kind of platform, we set out to design and find a camper that could support us on the trail for weeks or even months.

Can you tell us about your truck camper and why you chose that particular make and model?

Steve and Kirsten: After over 40 years of camping, we had a clear idea of what we needed in a truck camper: usability, sustainability, and ease of repair while on the road. We’ve experienced both tiny and large camping platforms and knew that having practical spaces to sit, relax, and feel comfortable—especially during bad weather—was key to happy camper living. We also realized that “big” campers don’t always mean “big” spaces, and we wanted something light and nimble enough to maneuver easily through small villages and venture off-road when needed. Lightweight, multi-use spaces were a must.

We also needed to ensure we could sustain ourselves for extended periods, so ample water storage and power were high on our list. Finally, we wanted a camper that was easy to maintain. Being able to access, repair, or replace broken components without special tools or dismantling the whole rig was crucial.

After visiting various truck camper builders across the US and attending shows like Overland Expo, we chose Bear Adventure Vehicles in Santa Paula, California. There were many reasons for this decision, but chief among them was that Bear, a small US-based company, embraced our design ideas and built our dream camper at an affordable price. Orlando Mistrettra, Bear’s founder and CEO, has decades of experience designing and building high-end custom builds. His commitment to quality, usability, and customer satisfaction (rather than profit) was a major selling point. Another big factor was Bear’s use of  Total Composite’s patented four-season composite panel system, which provides exceptional thermal efficiency and durability without the structural issues associated with wood or aluminum.

Does the camper have anything unique or custom about it?

Steve and Kirsten: Yes. Our camper, which we call “OSO,” is essentially a custom build at the price of a mass-produced rig. Many of its design elements draw inspiration from the marine and tiny house communities. One of the most unique aspects is its use of 48 volt power, rather than the typical 12 volt. This allows for a lighter setup and more effective components. We use advanced lithium server rack batteries, a 48 volt DC Air Conditioner, a large marine compressor fridge, portable induction cooking, hydronic diesel heat, and an advanced DC-to-DC alternator charger.

What are your favorite camper features?

Our favorite features are the camper’s layout/design and its off-grid sustainability. The bright and spacious rear area features a U-shaped couch that seats four to six people, complete with a marine-style folding table that lowers to create a queen-sized bed/lounge area. Surrounded by large Tern windows, this spot provides 270-degree visibility, making it perfect for relaxing and enjoying the views.

The front of the camper is home to a cozy 6-inch memory foam queen-size bed, with plenty of storage both beneath and around it, plus USB-C charging ports and portable lights for a relaxing reading/sleeping space. The wide center aisle between the bed and the U-shaped couch ensures easy access to all the camper’s essentials. The flatbed configuration provides ample storage space—we’ve gone over a month without needing to restock. With over 60 gallons of filterable water in three separate tanks, reducing contamination concerns, and a CompoCloset Cuddy composting toilet so there is no need to stop to dump holding tanks, as we have none. Solar power or diesel from the truck engine keeps our batteries charged, and the camper is equipped with both a DC air conditioner and an Aqua-Hot hydronic diesel heater, allowing us to camp comfortably in all weather conditions. Additionally, the entire flatbed camper can be removed from the truck and set on jacks, turning it into an off-grid tiny house base station.

Can you tell us about your camper’s electrical system including your solar power and DC-to-DC charger system?

Steve and Kirsten: We utilize two EG4 48 volt LiFO server rack batteries and EG4’s 5,000 watt inverter/MPPT controller. The batteries provide in excess of 800 amp hours of use, come with a 25 year warranty, and are nearly half the price and weight of automotive LIFO batteries of similar capacity. Further, being 48 volts allows lighter and more efficient wiring, the EG4s also have an advanced BMS and built-in fire extinguishers protecting the batteries condition and our rig. OSO has 800 watts of CIGS (Copper IIndium Gallium Diselenide) solar on the roof. These thin film flexible panels are hyper absorbent to work better in low light conditions and continue to operate even if/when significant portions of the panel are shaded. They are from the military and as such are nearly indestructible (you can walk directly on them) and are not affected by heat as much as traditional panels. Further, CIGS are lightweight and do not require any rack or drill through mounting frames. The entire 800 watt system is less than 35 pounds. Lastly, we utilize a Sterling 12 volt to 48 volt DC to DC alternator charger from the marine world that allows us to efficiently charge the 48 volt batteries from the engine. The Sterling is programmable allowing selectability of amp draw and even reverse “jumper” charging should the two 12 volt deep cycle engine batteries need it.

Can you tell us more about your truck?

Steve and Kirsten: Our truck, “Toro,” is a 1998 Dodge 2500HD club cab, long bed 4×4 with the legendary 12-valve Cummins 5.9L diesel engine and a six-speed manual transmission. It was originally a Canadian heavy-duty work truck, with a one-ton D-80 rear axle and upgraded frame. Toro has over 250,000 miles and, despite its age, has no rust thanks to the Canadian paint seal option. One unique feature is that both rear club cab doors open, yet it retains the 12-valve P-pump Cummins engine—a combination some Cummins fans refer to as a “unicorn truck.” To improve reliability and fuel efficiency, I’ve made several upgrades to the engine, focusing on better MPG. With fuel being our largest expense, we aim for slow travel and aim to achieve around 16 MPG. Other significant upgrades include replacing the stock suspension with a Carli Pintop system and swapping the steel bed for a lightweight Summit Expedition Truck (SET) aluminum flatbed to mount the camper.

Have you made any modifications to your truck to carry your truck camper or improve its ride?

Steve and Kirsten: Yes, we’ve installed a full Carli Pintop suspension system, including Deaver XXHD leaf springs, Thuren front track bars, and Timbren SES rear bump stops. We also upgraded to 17-inch heavy-duty aluminum wheels.

We love your aftermarket truck bed. Can you tell us more about it?

Steve and Kirsten: Yes, Oso has a Summit Expedition Truck (SET) aluminum 8 ft flatbed with side compartments and a rear drawer. The additional storage is a game changer—it helped us relocate gear that used to clutter the truck or camper, such as leveling blocks, tools, and electrical plugs.

Does your rig feature any other accessories or features worthy of note?

Steve and Kirsten: One standout feature is the 48 volt DC split air conditioner, made by Undermount who told us ours is the only one they know of to be mounted on a truck camper. The system runs directly off the 48 volt batteries, with no need for an inverter, shore power, or a generator. It can run indefinitely on solar power and/or the DC-to-DC alternator charger. On our first trip with OSO, we used the AC in 115F weather and kept the camper at a cool 74F. Another feature is the “mechanical space” located under the front counter providing easy access to all of the electronics and components.

Do you have any plans for future upgrades or modifications?

Steve and Kirsten: We’re considering a rear disc brake conversion to replace the OEM drums and improve braking performance. We also plan to refabricate the flatbed mounting brackets to lower the rig by 2-3 inches.

Do you have any regrets in your choices? Anything you wished that you had done differently?

Steve and Kirsten: Oso is a little taller, at just under 11ft, than I would have wanted. I believe we could have lowered the flatbed mounting brackets by about 2-3 inches but I was eager to use it so I did not pursue fabricating new brackets. While a small change, we have already run into remote train overpasses we could not fit under and had to find an alternative path around. Specific to the camper, I would probably modify the couch cushions making them thicker foam and add an electrical outlet outside the camper.

What kind of mileage do you get when hauling your truck camper?

Steve and Kirsten: Fuel economy depends on terrain and speed. On average, we get about 15 MPG. During our latest Baja trip, where we drove no faster than 55 mph, we averaged 16.2 MPG. On a recent Alaska/Canada trip with more freeway driving at 65-70 mph, we averaged 14.5 MPG. The worst was 6 MPG in 4-low uphill sand for four hours, and the best was 24 MPG driving downhill with a tailwind from Flagstaff.

What tires do you have on your truck and what inflation values do you typically run when driving on and off-road?

Steve and Kirsten: We run Falken Wildpeak 285/70/R17, load range E tires. On the road, we typically inflate them to 55 PSI front/60 PSI rear, and off-road, we reduce them to 20 PSI front/25 PSI rear.

Where have you taken your rig thus far?

Steve and Kirsten: We have been all over Baja, across the US, and as far north as Tuktoyaktuk on the Arctic Ocean at the end of the Dempster Highway in NWT Canada. In the last six months we roamed all around the Southwest. Starting at the Hoover Dam, we camped in the Valley of Fire. We roamed all around the silty, dead-end dirt roads of the Arizona Strip to the North Rim of the Grand Canyon checking out Native American rock art and ruins like Paiute Cave and in the Vermillion Cliffs National Monument area.

We continued onto Flagstaff then to Show Low eventually making our way to New Mexico spending time in El Malpais National Conservation Area. We then headed north up the Jimenez River Valley enjoying the natural hot springs before we explored Bandelier National Monument. Looking to restock we stopped in Los Alamos and checked out the history of the Manhattan Project before heading into Colorado and camping in Mancos and Durango. Heading down across the Navajo/Hopi Reservation we spent some time with family in the Phoenix area (camping in their driveway). We continued south past Tucson, camping in Madera Canyon then heading to Fairbanks and Tombstone enjoying the history. We visited Whitewater Draw to view the Sandhill cranes then continued south and east skirting the Mexico border looking for Jaguars.

We found nothing but great camping and an amazing museum outside Portal on the backside of the Chiricahua mountains. Taking the rugged, dirt road through the mountain pass, we dropped into Chiricahua National Monument enjoying hikes and watching troops of Coatimundis. Needing to get back home, we spent our last few nights camping near Cochise stronghold and exploring some really neat museums in the area like the Amerind, a must see.

Where are you planning to take your rig in the future?

Steve and Kirsten: This year, we’re planning a trip through the Pacific Northwest into British Columbia, then across the US to Newfoundland, Nova Scotia, and back down the eastern seaboard before heading west to San Diego.

Do you have any social media channels where our readers can follow you?

Steve and Kirsten: Yes, you can find us at KiandSteve on both Facebook and Instagram.

This has been great talking to you. Thanks again for taking the time to talk with us. Do you have any final advice for our readers?

Steve and Kirsten: Just get out there and explore—it’s the best way to figure out what works for you and what you really need in a rig.