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.
The cheapest and the priciest cities in Arizona. Bullhead City is the cheapest place to live in Arizona, earning a 91.7 composite score in the Cost of Living Index. Pictured is nearby Davis Dam, which stretches from Nevada to Arizona across the Colorado River to form the Mohave Lake. Getty Images/Panoramic Images.