Colorado Hwy 149 south of Lake City
Lake San Cristobal and the San Juan Mountains. The lake follows the edge of the Lake City Caldera from the mid-tertiary volcanic period.
Looking West from Windy Point overlook towards the San Juan Mountains. The tallest peak is Uncompahgre Peak. Most of the peaks are from middle-phase Tertiary lava flows.
Southwest from Windy Point overlook is the edge of the Lake City Caldera on the right lower half of the field. Red mountain (midright top) and Grassy mountain (midleft top) are also from middle-phase lava flows. Igneous influx of metals (silver, gold) around the Lake City Caldera made it a very rich mining center.
Hwy 149 allowed us to reach the continental divide for the 4th time on our trip.
Basalt column ridge and aspen near Clear Creek.
North Clear Creak Falls over Nelson Mountain Tuff which originated from a volcanic eruption 27 Ma.
The San Juan Mountains in the distance drain water into a valley which is the origin (headwaters) of the Rio Grande River.
Colorado Hwy 149 headed South towards Creede passes near the towering outer rim of the Creede Caldera composed of basalt from middle Tertiary lava flows.
Roadcut basalt near Creede.
Creede, CO against the Creede caldera wall. Heavy igneous infusion of metals along the caldera made this a very rich Silver mining center. It is now a tourist center.
The Rio Grande River cuts through the Creede Caldera outer rim.
Hwy 149 passes through a cottonwood grove with the Creede Caldera rim on the left.
Royal Gorge and bridge near Cañon City. The geologic history is similar to Black Canyon of the Gunnison.
Montage of Great Sand Dunes National Park. Winds blowing from the Southwest from the San Luis Valley deposited sand in an area protected by 3 low passes in the Sangre de Cristo mountain range. Most of the sand probably was deposited in the Pleistocene (10,000 years ago).
Great Sand Dunes National Park
