"We can see the Dunes and the Crestone Needles from all over our ranch. When we are lost, that's what we navigate by."
Whether traveling on foot, by horseback, Model A, or the latest-model car, the dunes and mountains behind them were—and still are—used as landmarks by travelers in and around the San Luis Valley. The oldest evidence of humans in the area dates back to about 11,000 years ago. Perhaps echoing your own experience in driving here, those people probably saw the dunes as a tan blur in the distance from miles away.
On the far horizon, the San Juan Mountains rim the San Luis Valley to the west. Behind you, mountain passes through the Sangre de Cristo Mountains were used by people traveling between the San Luis Valley and communities to the east. The Medano Pass Primitive Road (4-wheel-drive, high clearance required) and the Mosca Pass trail both follow rough historic routes over the Sangre de Cristo Mountains.