Skip to main content

Arizona State Route 366 and Mount Graham

The photo below was taken back in 2012 from US Route 70 near Safford looking south towards the 10,724 foot Mount Graham near Safford in Graham County.  Mount Graham is the location of one of the few Arizona State Routes I never fully finished; AZ 366.






Arizona State Route 366 is a 28.33 mile state highway running west from US 191 in Swift Trail Junction to the Columbine Ranger Station of Coronado National Forest.  While AZ 366 doesn't technically go all the way to the summit of Mount Graham it does provide access to it via connecting National Forest Routes.  Approximately the first 22 western most miles of AZ 366 are paved while the remaining portion of the route is gravel.

AZ 366 was established as a State Highway in 1960.  The numbering convention of "366" comes from the connection the route had with US 666 which was eventually renumbered in Arizona to US 191.  Prior to the Interstates being built all Arizona State Routes had a number that was consecutive of a US Route.   Initially the routing of AZ 366 was reportedly only about 6 miles west from US 666 Swift Trail Junction but was quickly expanded to the modern 28.33 miles.  This 1961 Arizona State Highway Map shows the full routing of AZ 366 much as it appears today.

1961 State Highway Map 

AZ 366 appears to be not much more than a maintenance swap between ADOT and Coronado National Forest.  The eventual routing of AZ 366 appears as "Swift Trail" on the 1956 Arizona State Highway Map.

1956 State Highway Map

The summit of Mount Graham is the location of the Mount Graham International Observatory which began operations in 1993.  Mount Graham is one of five Ultra-prominent peaks in Arizona which have prominence of over 5,000 feet above the surrounding terrain.  Mount Graham ranks 50th overall in the United States in terms of prominence at 6,340 feet above the surrounding terrain.

Comments

Popular posts from this blog

Former US Route 50 and the Pioneer Route Lincoln Highway on Johnson's Pass Road

Johnson's Pass Road is one of the oldest highway corridors in California.  Johnson's Pass was part of the Lake Tahoe Wagon Road as it was completed during 1856 over the Sierra Nevada.  The pass would later be incorporated into the Pioneer Branch of the Lincoln Highway in 1913 and US Route 50 in 1926.  Johnson's Pass Road would be bypassed by a new alignment of US Route 50 over Echo Summit in 1938.  A replacement of the Meyers Grade east of Johnson's Pass would be opened to traffic in 1947.   Johnson's Pass Road remains accessible to traffic and is still signed by the Lincoln Highway Association.  Pictured as the blog cover is the view from the top of Johnson's Pass Road overlooking modern US Route 50 and Lake Tahoe.   Part 1; the history of Johnson's Pass Much of the history of what become the Lake Tahoe Wagon Road is discussed in the  September 1950 California Highways & Public Works  during its Centennial Edition.  The or...

Former US Route 50 and the South Lincoln Highway from Folsom east to Placerville

The corridor of Folsom of Sacramento County east to Placerville of El Dorado County has been a long established corridor of overland travel dating back to the California Gold Rush.  The Folsom-Placerville corridor was once part of the path of the Lake Tahoe Wagon Road which became the first California State Highway and later the South Lincoln Highway.  In time the South Lincoln Highway's surface alignment was inherited by US Route 50.  The Folsom-Placerville corridor also includes the communities of; Clarksville, Shingle Springs and El Dorado. Part 1; the history of the Lake Tahoe Wagon Road, South Lincoln Highway and US Route 50 through Folsom-Placerville Folsom is located on the American River/Lake Natoma of eastern Sacramento County.  That lands now occupied by the City of Folsom were part of Rancho Rio de los Americanos prior to the finding of gold at Sutter's Mill during 1848.  During the California Gold Rush the lands of Rancho Rio de los Americanos were p...

Angus L. Macdonald Bridge

At 1.3 kilometers (or about 0.84 miles) in length, the Angus L. Macdonald Bridge is one of two bridges crossing over the Halifax Harbour between Halifax, Nova Scotia and Dartmouth, Nova Scotia, with the other bridge being the A. Murray Mackay Bridge . Opened in 1955 and named after former Nova Scotia Premier and Canadian Minister of Defense for Naval Services Angus L. Macdonald, the Macdonald Bridge was the first bridge that crossed Halifax Harbour that was opened to traffic. The Macdonald Bridge was also the subject of the Big Lift, which was only the second time in history that the span of a suspension bridge were replaced while the bridge was open to traffic. Planning began in 2010 for the Big Lift, while construction took place between 2015 and 2017. Similar work occurred on the Lion's Gate Bridge in Vancouver, British Columbia before the project took place on the Macdonald Bridge. At this time, much of the bridge infrastructure is new, leaving only the towers, main cables and...