The Big Rentals Guide to Towing an Enclosed Trailer in and around Denver, CO

An enclosed trailer keeps the weather off your cargo, and around Denver the weather and the road both go up. People rent enclosed here to keep mountain snow, cold and grime off what's inside, but the same tall box that protects the load is a handful on I-70's grades at altitude, where it catches wind and works the brakes coming down.

Load it heavy against the doors and it shifts on a grade you can't see into. Take a tall box up a pass in a crosswind unprepared and it pushes back. Ride the brakes down from the divide and fade them. This guide covers the enclosed sizes that match real Denver loads, the Colorado rules that apply the second you couple up, and the grades, altitude and weather that make an enclosed trailer rental in Denver its own particular job.

Why Denver Renters Choose Enclosed Trailers

Front Range growth means constant moves, and an enclosed trailer keeps furniture, boxes and gear dry through spring snow and mountain weather. It's the default here for anything that can't take the weather. Read more about when an enclosed trailer is worth the extra cost over an open one.

Gear headed to the mountains is the other draw: bikes, ski and snowboard gear and valuable equipment ride enclosed to keep mountain weather and road grime off them on the way up. And the region's trades and build-out keep tools, equipment and materials moving in a locked box that stays dry and secure, much of it cycling into and out of storage on the calendar.

Whatever you're carrying, you'll find trailer rentals across the Denver area from local owners near you.

Colorado Towing Laws Every Enclosed Trailer Renter Should Know

Brakes and the breakaway

Colorado requires brakes on all wheels and a battery-powered breakaway at 3,000 lb, able to stop the trailer within 40 ft from 20 mph (CRS 42-4-223). A loaded enclosed trailer clears 3,000 lb, so all-wheel brakes and a charged breakaway are a given, and they matter most on a descent. Confirm the brakes, the breakaway and your tow vehicle's brake controller, and check the gross vehicle weight rating (GVWR) before you book. Read more about what GVWR means and how to read it.

Securing the load you can't see

Colorado requires the load secured so nothing shifts. Inside a closed box that means strapping the load so it can't move against the doors or walls, with the heavy items low and forward. On a grade, a load that shifts moves the whole trailer's balance, and the walls hide exactly what's moving until you feel it. Read more about how to secure furniture and appliances in an enclosed trailer.

Speed, the Express Lanes and size

Colorado sets no separate towing speed limit, so the posted limit applies, but on the mountain corridors the grade sets your real speed. Colorado's Express Lanes don't ban trailers the way Texas, California and Utah do, but they're HOV3+ or toll lanes, so a truck towing a trailer would need three or more occupants or an ExpressToll pass and toll to use them — and the general lanes are the better choice with a tall box on the grades anyway. Width is capped at 8 ft 6 in, height at a generous 14 ft 6 in, and a standard license covers the haul.

Matching an Enclosed Trailer to Your Vehicle and Load

Sizing

Common enclosed sizes run from 5x8 up to 8.5x24. A 5x8 to 6x12 handles gear and small moves; a 7x14 to 8.5x24 covers full moves and large equipment. Interior height is the dimension people forget until a tall item won't stand up, so measure the tall things. Read more about choosing the right enclosed trailer size for your load.

Hitch, brake controller and tracking

Match the trailer's coupler to your ball size, confirm the brake controller and set the trailer up balanced so a tall box tracks straight, which also keeps it steadier in mountain wind.

Balance and the load you can't see

Aim for 10% to 15% of the load weight on the tongue. Because the walls hide the load, it's easy to stack the heavy items against the back doors and build a sway you won't feel until a gust or a grade finds it, so load heavy items low and forward of the axles and strap them so nothing migrates. Read more about the common mistakes people make when renting an enclosed trailer.

Altitude margin

Thin air cuts the tow vehicle's power, so leave margin on a load you'll take up a pass — the rig that felt strong in town has less in reserve on a long climb.

The Grades, the Altitude and Mountain Weather

The box is protection and a sail

The enclosed trailer's value is that it keeps snow and grime off the cargo, but a tall, relatively light box catches crosswinds on I-70 and the open stretches, and a gust hits harder on snow or ice. Slow down and give yourself far more stopping room than the dry-valley version of the same trip.

Down the grade without cooking the brakes

Gravity plus a tall loaded box fades brakes on a long descent, so downshift and let the engine hold your speed rather than riding the pedal, watch for the runaway-truck ramps, and recheck the load before the descent so nothing shifts once you're committed.

Altitude on the climb

The same thin air that thins your brakes' margin thins your engine's power, so plan a lighter load or a stronger truck for a mountain haul and keep your temperature gauge in view.

Winter traction

Colorado posts traction and chain requirements on I-70 in winter, and a tall enclosed box on a snowy grade is not the place to be caught out, so check CDOT conditions before you head up and don't take it over a pass in a storm.

Insurance and Damage Protection

What about insurance and damage protection?

Before towing a rented trailer, contact your auto insurance provider to ask whether your policy covers liability and towing-related damage claims.

Eligible rentals booked through Big Rentals also include Basic Rental Protection at checkout. This added protection can help limit your financial responsibility for certain damage or theft events during the rental period.

For full details on how Basic Rental Protection works, including deductibles, exclusions, and renter responsibilities, review our FAQ and platform terms.

Ready To Book?

Get the size right, confirm brakes and a breakaway, secure the hidden load, and respect the box in mountain wind and on the descents. Do that and an enclosed trailer is the most reliable way to move cargo that can't take the weather across the Front Range and up to the mountains. When you're ready, browse enclosed trailer rentals in Denver from local owners near you.

The Short Version

• Enclosed trailers are Denver's choice for weather-proof moves, mountain-bound gear and trade equipment that can't ride open.
• A loaded enclosed trailer is over Colorado's 3,000 lb threshold, so all-wheel brakes and a battery breakaway are a given (CRS 42-4-223).
• Secure the hidden load so it can't shift against the doors — on a grade, a shifting load moves the whole trailer's balance.
• No separate towing speed limit — the grade sets your real speed — and Colorado's Express Lanes don't ban trailers but are HOV3+ or toll, so the general lanes are the better choice on the grades.
• The box protects the cargo but catches wind on I-70, so slow down, downshift on descents, and leave altitude margin on the climbs.
• Check CDOT for traction and chain requirements in winter, and keep 10% to 15% of the weight on the tongue.