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

California State Route 58/Old California State Route 178 west of CA 43

This past week I drove California State Route 58 west of CA 43 in Kern County over the Temblor Range and La Panza Range to US Route 101 near Santa Margarita of San Luis Obispo County.


CA 58 west of Bakersfield and CA 99 in general is a mostly two-lane highway that traverses some very remote territory of Central California.  I chose to cover CA 58 west of CA 43 specifically due to the changes in the alignment that are to come when the West Side Parkway connects to the Centennial Corridor project.  The Centennial Corridor will connect CA 58 west of CA 99 to the already completed segment of Freeway on the West Side Parkway.

Westside Parkway and the Centennial Corridor; Future California State Route 58

CA 58 from Barstow west to Bakersfield was carved out of what was US Route 466 during the 1964 State Highway Renumbering.  CA 58 west of Bakersfield to Santa Margarita was carved out of what was part of CA 178.  The change from CA 178 to CA 58 west of Bakersfield to Santa Margarita can be ob…

California State Route 118

This past month I drove the entirety of California State Route 118 from Ventura County east into Los Angeles County.


CA 118 is a major 47 mile State Highway which begins in the City in Ventura County and traverses east into Los Angeles County by way of Simi Valley and Santa Susana Pass.  From Santa Susana Pass CA 118 continues eastward through San Fernando Valley within the City of Los Angeles and terminates at Interstate 210.  CA 118 contains within it's right-of-way some of the most historic highway corridors in California history.

The precursor route of CA 118 was Legislative Route Number 9 which was first added to the State Highway System during the First State Highway Bond Act of 1909.  The original definition of LRN 9 was from San Bernardino westward to LRN 4 in San Fernando. LRN 9 was extended westward to LRN 2 near Montalvo (modern day Ventura) in 1933.

In a August 1934 Department of Public Works Guide the Signed State Highways were announced.  CA 118 was announced to be a…

Chisholm Ferry/Bridge Location and early Legislative Route Number 10

This past month while viewing the site of Chisholm Ferry along the Kings River of Kings County I noticed that route being illustrated resembled an early Californian State Highway.  My suspicions proved correct as the location of Chisholm Ferry was part of the original alignment of Legislative Route Number 10; a precursor to California State Route 198.


The Facebook in question above was posted on the Antique Images from the Collection of Michael J. Semas and can be viewed below:

Michael J. Semas on Chisholm Ferry and Bridge

The location of Chisholm Ferry is located just south of Jackson Avenue/Old CA 198 on the Kings River about 4 miles west of Lemoore near Avenal Cut-Off Road.  This particular section of the Kings River was once the northern most extent of Tulare Lake.

Tulare Lake was once the largest fresh water lake west of the Great Lakes by surface area.  Tulare Lake was first surveyed at an approximately 570 square miles in 1849 and was later surveyed to be 690 square miles in …