La Garita (or La Ventana) Natural Arch is different from many of the natural rock arches scattered around Colorado. Rather than being formed from uplifted sandstone as most arches are, the Ventana Arch formed within a magma intrusion called a volcanic dike.
Lava from the Summer Coon volcanic complex intruded into cracks in the surrounding alluvial and volcanic deposits about 30 million years ago. Parts of the magma cooled at different rates and separated from the rest of the wall, and when the surrounding deposits eroded away, the inner part of the arch collapsed, leaving a hole in the dike. The end result was a 40-foot-tall, 30-foot-wide arch.
From the end of La Ventana Road, a steep scramble leads to the arch, rewarded with views across the San Luis Valley to the Sangre de Cristo mountains and the Great Sand Dunes National Park. The arch itself is difficult to see from any direction except directly in front of or behind it, quite clearly from the parking at the end of La Ventana Road. If you want to scramble up to the rock wall, bikes can be left at the end of the road, ideally locked in an elevated position, and can be seen when looking back while hiking up.
The arch is a sacred site for the Jicarilla Apache and Ute tribes and is still used for ceremonies.
The arch is about 11 miles northwest of Del Norte, Colorado, on Forest Service Road A23, a.k.a. La Ventana Road. The road is rough rocky gravel, but doable on most bikes. Signs in the area point to the arch. When hiking to the arch, wear sturdy shoes with good grip. Caution is warranted when climbing to the arch and when descending. Loose rock requires caution and stable footing.
To get to the Arch from Monte Vista – head north out of Monte Vista on Highway 285 for 18 miles to County Road G. Turn left and go west to the “Y” just past the La Garita Store. Take the dirt road south and follow the signs to the Natural Arch.