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.
Arizona Mountain Ranges Highpoints List, 204 peaks, Revised September 18, 2012. Mountain Ranges are arranged alphabetically. The list contains 193 ranges with their highest points in Arizona. The last 11 ranges extend outside the state and the highest peak lies in an adjacent state or country (Mexico). The highest part of these ranges in Arizona are listed in the 193.