PPT Slide

Previous slide

Next slide

Back to first slide

View graphic version

Also, at that time there were no major mountain ranges to the west of present day Colorado. Thus, there was nothing to block storms from the Pacific Ocean from carrying moisture to the area. Today, the coastal ranges, the Sierra Nevada and Cascades, block many of the moisture laden clouds, causing a rain shadow. The moisture falls on the western flanks of those mountains and results in a much wetter climate on the west side than on the east.