Subdivisions. The Ordovician is the second period of the Paleozoic era. The Ordovician began after the end of a series of extinction events known as the Ordovician-Silurian extinction events which ended around 488 mya.
As a state highpointer, Humphrey's Peak in Arizona was on my bucket list. The trailhead was easy to find. The trail itself was not well maintained and rather rocky, which wasn't too bad going up, but required a lot of caution descending to protect your knees.
This map shows the major streams and rivers of Arizona and some of the larger lakes. Arizona is in the Pacific Ocean Watershed and most drainage leaves the state through the Colorado River. Most of these lakes and streams can be clearly seen on the Arizona Satellite Image.t shows elevation trends across the state. Detailed topographic maps and aerial photos of Arizona are available in the Geology.com store. See our state high points map to learn about Humphreys Peak at 12,633 feet-the highest point in Arizona. The lowest point is the Colorado River at 70 feet.