At one time, U.S. Route 80 ran across the southern tier of the country from coast to coast. The western terminus was San Diego, California, and the eastern terminus then and now is just east of Savannah, Georgia. The western course of U.S. 80 was decommissioned, so the route now terminates in Dallas, Texas. Portions of the route west of Dallas still exist and in Arizona have been designated as Historic U.S. 80 as the sign above shows.
Recently, I was driving from Phoenix to Oracle, Arizona, for a conference. Somewhat east of Phoenix, signed Historic 80 veers off from U.S. Route 60 to become Historic 80’s northernmost point of the section that I drove down. This interchange is called Florence Junction. The official designation of the road is Arizona State Route 79 (SR 79). Florence, Arizona, is the first town south of Florence Junction, about 14 miles distant. I would like to spend a couple hours in Florence to get a feel for the town.
Historic 80 then continues southward toward Tucson, Arizona, over SR 79 until this numbered road reaches SR 77 and terminates. This location is called Oracle Junction. The original U.S. 80 proceeded from here to Tucson and beyond.
See where SR 79 is on Google maps:
The distance between Florence Junction and Oracle Junction — the length of SR 79 — is about 42 miles. That’s about the same distance as between downtown Phoenix and Florence Junction! Metropolitan Phoenix has spread out along this entire corridor. This is a perfect example of urban sprawl. In contrast, the land south of Florence Junction is undeveloped grazing range land, and I hope that it stays that way.
On this trip, I was interested in reaching Oracle, east of what is aptly called Oracle Junction. The way from Oracle Junction to the town of Oracle, Arizona, is over SR 77 eastward. The most prominent landmark here is towering Mt. Lemmon. Mt. Lemmon is the highest peak in the Santa Catalina mountain range. This mountain range is in the Coronado National Forest which spans southeastern Arizona.
I like this description of this national forest: “The Coronado National Forest spans sixteen scattered mountain ranges or ‘sky islands’ rising dramatically from the desert floor….” (This quote is attributed to the Home page of the Coronado National Forest, but I can’t find it there.) You can see Mt. Lemmon as a sky island in my photo above. The drive from Phoenix to the foot of Mt. Lemmon is entirely a desert floor. As you drive, the elevation gradually rises. Oracle, Arizona, is actually about 3,100 feet higher than Phoenix. It lies northeast of the foot of Mt. Lemmon in a transition zone between the desert floor to the north and the sky island of the national forest. This transition zone is narrow.
All along the trip from Phoenix to Oracle one sees subtle changes in the plant ecology. For example, Saguaro cactuses grow in the lower elevations where there are no freezes during the winter. At some point in the trip, the weather brings freezing temperatures to the desert floor, and Saguaros can’t survive a freeze. One also sees this on a trip north from Phoenix to Flagstaff, Arizona. At first, there are Saguaros everywhere. Then they grow only on the south side of mountains, the warmer side. Then they disappear. The temperature freezes over at night in the depth of winter.
The Arizona Department of Transportation has a web page describing the history of U.S. 80 in Arizona.
Also see the Arizona Daily Star, Photos of U.S. Route 80 through Arizona,