Here is a picture of the west peak of a twin pair called the Spanish Peaks. The picture was taken about 5 miles south of LaVeta Colorado about a mile west of highway 12. The rock wall below the peak is called a dike. When the molten magma was rising in the Earth it was also moving through vertical cracks and joints, spreading out in all directions like the spokes of a wheel. As erosion has occurred these dikes have become exposed. They vary from 1 to 100 feet wide and up to 14 miles long. The dikes are a prominent feature of the landscape around the Spanish Peaks as they eminate radially out from the center of the peaks. You can get more info and see some more pictures at www.sangres.com/mountains/spanpks.htm .
I'm lucky enough to have 35 acres in this area that I'm going to be building our retirement home on in the next year.