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.
From Wikipedia, the free encyclopedia. Mount Lemmon (O'odham: Babad DoÊ¼ag), with a summit elevation of 9,159 feet (2,792 m), is the highest point in the Santa Catalina Mountains. It is located in the Coronado National Forest north of Tucson, Arizona, United States. Mount Lemmon was named for botanist Sara Plummer Lemmon, who trekked to the top of the mountain with her husband and E. O. Stratton, a local rancher, by horse and foot in 1881. It is reported that Mount Lemmon Ski Valley, on the mountain's northeastern side, receives 200 inches (508 cm) of snow annually.