The red in Red Rock Canyon is rust. Iron oxide seeped through dunes that hardened into Aztec sandstone roughly 180 million years ago, when a sand sea the size of the Sahara covered what is now southern Nevada. Cross-bedding from that vanished dune field still runs across the Calico Hills in visible diagonal sweeps. Above it sits gray Cambrian limestone, older by some 300 million years, carried east over the younger rock along the Keystone Thrust fault. The escarpment that frames a red rock canyon sunset horseback ride and barbeque dinner is, in stratigraphic terms, upside down. The human record here is shallower and stranger. Southern Paiute families left agave roasting pits and petroglyphs in the sheltered washes near Willow Spring, where seasonal water still draws bighorn sheep down from the ridgelines. In 1905 the Excelsior Stone Quarry began cutting blocks at the site now marked as Sandstone Quarry, and abandoned them where they lay when the venture failed. Ranchers followed the same springs. Spring Mountain Ranch, a watering stop on the Old Spanish Trail and later Howard Hughes property, kept working horses in the shadow of the Wilson Cliffs for more than a century. The riding culture behind today's Las Vegas sunset trail rides descends from that stock economy, not from tourism. Protection arrived late and in stages. The Bureau of Land Management designated Red Rock Recreation Lands in 1967; Congress elevated the area to Nevada's first National Conservation Area in 1990. It now covers roughly 195,819 acres of Mojave Desert along the eastern flank of the Spring Mountains and absorbs more than three million visits a year, a volume closer to a national park than to a typical BLM holding. The 13-mile one-way Scenic Loop Drive remains the spine, with marked pullouts at Calico I, Sandstone Quarry and High Point Overlook, and it is the corridor most red rock canyon sunset horseback ride and barbeque dinner tour operators use to reach the trailheads. What the conservation area preserves is contrast. Seventeen miles separate the lit frontage of the Strip from ground held by Joshua trees, blackbrush and wild burros descended from nineteenth-century mining stock. Threatened desert tortoise still occupy the alluvial fans below the cliffs. Air clarity and dark skies remain good enough that the Wilson Cliffs move from ochre to deep carmine in the final half hour of light, then flatten to blue within minutes. That narrow interval is the reason red rock canyon sunset horseback ride and barbeque dinner tours exist at all, and the reason Red Rock Canyon landmarks read as a different place after six in the evening.