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 north rim has two main viewpoints towards the east, reached by the side road. One is Point Imperial, the highest in the park at an elevation of 8,803 feet, which apart from the canyon, here relatively shallow and less branched, also overlooks large areas of the Painted Desert and the Navajo Reservation. The second is Cape Royal (7,865 feet), perhaps the best of the north rim sites. The cape is 20 miles from AZ 67, right at the end of the road which becomes rather narrow and twisting over the last couple of miles as it runs along a steep sided ridge.