Mosquito Pass

The Alpine Loop Backcountry Byway is a 65-mile network of historic mining roads connecting Lake City, Ouray, and Silverton through the San Juan Mountains at elevations above 12,000 feet, managed by the BLM Gunnison Field Office. The route crosses Engineer Pass (13,218 ft) and Cinnamon Pass (12,620 ft) on narrow, rocky mountain tracks with significant exposure. High-clearance 4WD is required at minimum; experience with mountain driving and a recovery kit are strongly recommended. Jeeps, 4x4 trucks, and side-by-sides are the predominant vehicles; ATVs are permitted on designated segments. No fee or permit is required; dispersed BLM camping is available at multiple pullouts along the route. One of the most celebrated 4WD destinations in the lower 48, drawing tens of thousands of vehicles each short summer season.

Grand Mesa National Forest hosts designated OHV trails across the top of the Grand Mesa — the world's largest flat-top mountain, a volcanic basalt plateau northeast of Grand Junction in Mesa County, Colorado, rising to over 11,000 feet above sea level. The Grand Mesa's flat-top geography is geologically unusual and recreationally distinctive: the mesa top is a rolling plateau of alpine meadow, aspen groves, and more than 300 small lakes and reservoirs sitting at 9,000 to 11,000 feet elevation, surrounded by the steep canyon walls that define the mesa's perimeter and separate the high plateau from the Colorado Plateau basin far below. Trail access is primarily via Highway 65 near the Lands End Road junction, which crests the mesa from the western side. The OHV routes traverse the mesa through mixed terrain: moderate forest doubletrack through aspen and spruce corridors at mid-elevations, alpine meadow traverses above treeline with the sweeping views across the Colorado Plateau that are the Grand Mesa's defining visual experience, and technical rocky routes on the approach ridges where the basalt cap produces the broken-rock surface distinctive of volcanic flat-top geology. ATVs, UTVs, and motorcycles are permitted on designated trails; Colorado OHV registration is required for all machines. Dispersed camping and developed campgrounds are available on the national forest at no additional trailhead fee. Season is approximately late June through October depending on annual snowpack — the 11,000-foot plateau holds snow well into summer in heavy years. Contact the GMUG Grand Junction Ranger District for current trail status and snow conditions (970-242-8211).

The Holy Cross 4WD trail system in the White River National Forest covers the technical mining-era roads of the Mount of the Holy Cross wilderness area flanks and the Minturn-Red Cliff corridor in Eagle County, Colorado — the mountain country between Vail and Leadville, at the heart of the central Colorado Rockies where the White River, Gore Range, and Sawatch ranges converge. Core trails include the Holy Cross Road (FR 759), the Red Cliff to Homestake Reservoir route, and the network of historic mining access roads through the Battle Mountain district. The terrain is characteristic central Rockies high country: subalpine spruce-fir forest from the valley floors at 8,000 feet up to treeline around 11,500 feet, rocky mining-era roads that follow the creek drainages and cross the exposed alpine tundra on the higher sections, and the dramatic topographic relief of the Eagle River valley system where the roads climb steeply from the valley bottoms to the ridge terrain. The Holy Cross Road is particularly well-known for its technical rock sections and the consequential exposure on the narrower passages — the trail is rated black diamond on most 4WD rating systems and regularly destroys underbuilt vehicles. Full-size 4x4 Jeeps and high-clearance trucks are the predominant vehicles; experience with technical mountain driving and a functional recovery kit are genuinely required rather than suggested. The Eagle River Ranger District of the White River National Forest (970-827-5715) manages the road system and posts current seasonal status, gate schedules, and damage reports. Dispersed camping is available under standard National Forest 14-night limits.

Phantom Canyon Road is a 30-mile historic unpaved route managed by the BLM Royal Gorge Field Office, running between Cañon City at the south end and Victor at the north through a dramatic narrow canyon following the former grade of the Florence and Cripple Creek Railroad — a narrow-gauge line that served the Cripple Creek gold camp from 1894 until 1912. The route's engineering heritage is its defining feature: two hand-carved rock tunnels bored through solid granite, elevated wooden trestle bridges spanning the canyon creek, and canyon walls that rise hundreds of feet on both sides to create a slot-canyon atmosphere unique among Colorado backcountry roads. Elevation ranges from approximately 5,500 feet at Cañon City to 9,500 feet near Victor, passing through multiple ecological zones from high desert to subalpine forest. Access is restricted to street-legal four-wheel-drive and high-clearance vehicles with combined vehicle length under 25 feet — standard-cab pickup or shorter. Two-way traffic on a one-lane route requires patience and etiquette at passing areas. Access is free with no permit required; dispersed BLM camping is available at pullouts along the route. The route passes through BLM land with private inholdings — respect posted closures. Conditions vary significantly by season; contact the BLM Royal Gorge Field Office (719-269-8500) before visiting in spring or after storms.