A High Plains Traveler Highway History Essay: The Changing West End of U.S. 70


U.S. 70 is a “x0 route”, one of the original 1926 routes ending in 0, numbers that were generally reserved for routes that crossed most if not all of the country and served major population centers. The west end of U.S. 70 was originally located at Holbrook, in northeastern Arizona. Under the original 1926 plan, that terminus would have been at U.S. 60, but before the routes were marked, original 60 became 66. During the early 1930s, there were several significant revisions to the western terminus of U.S. 70. Ultimately, the route made it all the way to downtown Los Angeles, and filled that cross-country role for around 30 years. With the development of the Interstate system, there was no need for this designation on top of a major cross-country Interstate highway, and the western terminus of the route was moved east to Globe, Arizona. This essay will summarize the shifting west end of this route, the reasons for moving this point, and some of the conflicting issues that made maintenance of the U.S. 70 designation in the far west questionable.

In this essay, AASHO is the American Association of State Highway Officials, which today is known as AASHTO, having added “Transportation” to their name. They have a storehouse of documentation relating to U.S. and Interstate highway numbering decisions from 1925 to the present that is available on line. While it isn’t complete, a lot of information relating to early numbering decisions is available.

Original Terminus (1926-30)

The current route of U.S. 70 across New Mexico and Arizona has almost completely changed from the original routing approved in 1926. Only the few miles from Clovis, NM east to the Texas border is the same. U.S. 70 crossed New Mexico in an almost straight east-west line, heading west from Clovis to ultimately intersect U.S. 85 north of Socorro, then follow U.S. 85 to Socorro and then head west from Socorro to Arizona. In Arizona, it traveled west to Springerville, then northwest from Springerville to intersect U.S. 66 at Holbrook.

This first map, from 1930, shows the original routing of U.S. 70 across New Mexico. The later routing of U.S. 70 is also plainly visible here, shown as U.S. 366 heading southwest from Clovis to Roswell and Alamogordo. There is also a short U.S. route 470, which starts just west of Willard and follows present-day NM 41 to Moriarty, then west through Tijeras Canyon to Albuquerque. At this time, U.S. 66 was still routed northwest from Santa Rosa to just west of Las Vegas, then northwest through Santa Fe and south to Albuquerque, so this route was the gateway to the east side of Albuquerque.

1930 Official New Mexico highway map. Yellow outline is U.S. 70 prior to rerouting, blue line is U.S. 470.

Likewise, this map shows the Arizona routing. This was published in 1930-31, around the time U.S. 60 was extended west, so it also shows the new U.S. 60 designation that partially replaced 70 in far eastern Arizona. Prior to that time, U.S. 60 did not exist in Arizona, except as the original designation for U.S. 66. The yellow line is the part of 70 that was replaced in 1931 by U.S. 60, and the blue portion was replaced by a new U.S. 260.

1931 Official Arizona Highway Map, which also shows the pending extension of U.S. 60. Yellow line is U.S. 70 later replaced by 60, blue line is U.S. 70 later replaced by 260.

Major Route Changes 1931-35

The first major change to the west end of U.S. 70 was brought about by the extension of the final 1926 iteration of U.S. 60. The original western terminus of U.S. 60 was Springfield MO. As noted in the introduction, there was a desire to extend U.S. 60 in order to have that x0 route extend as far west as possible, and so states west of Missouri petitioned AASHO to extend 60 westward. In late 1930, AASHO approved a westward extension of U.S. 60, using original U.S. 366 west through Amarillo to Clovis, NM. From there 60 would replace U.S. 70 across New Mexico and far eastern Arizona. West of Springerville AZ, U.S. 60 was planned to follow a new road that would go through Show Low and down the Salt River canyon to Globe; however, that road was not yet built, and so 60 followed a temporary route down what is now AZ 73 to Fort Apache, and south across the San Carlos Apache Reservation to the town of San Carlos. It then was routed through Phoenix, and over newly improved state highways to the California border at Blythe. U.S. 60 was designated all the way to Los Angeles in this extension. AASHO makes an interesting comment during this process: they didn’t want to maintain 60 and 70 across New Mexico for a long distance because the AASHO numbering committee wouldn’t approve such a long concurrency, so a change in the routing of U.S. 70 was necessary. (Keep that in mind in tracing the future routing of 70). U.S. 70 northwest of Springerville to Holbrook became a newly designated U.S. 260, which originally was a short, single state route.

Unfortunately, the minutes for the approval of the extension of U.S. 60 and the rerouting of U.S. 70 don’t contain discussions at AASHO meetings. Also, there is no correspondence in available AASHO files. But, in 1930-31, U.S. 70 was routed southwest from Clovis NM, through Roswell to Alamogordo, and then south to El Paso, replacing U.S. 366. That 366 designation was immediately recycled on the short U.S. route 470 from original U.S. 70 to Albuquerque. At the time of this rerouting, the highway between Las Cruces and Alamogordo was not improved to the point where it could have been incorporated in to a U.S. route. I miss seeing any correspondence, because New Mexico is very much on the record in 1934 and 1935 as decisions are made to reroute U.S. 70 westward.

The Final Rerouting West: 1934-35

It seems from a review of AASHO correspondence during the early to mid 1930s that they were acting independently of the states in making changes to the U.S. highway system. There are many mentions of a study to revise and consolidate the system in the early 1930s, and a major set of changes were approved in June, 1934. Unfortunately, the changes were so massive that the list was not included in AASHO minutes of this meeting. One change that was made, though, was a revision to U.S. 70 that the New Mexico Highway Department did not approve of.

The original 1926 U.S. route system in Arizona and New Mexico included a U.S. 180, which has no connection to the present-day U.S. 180. Its west end was at the junction of U.S. 80 at Florence Junction, and it went east through Safford to Lordsburg, NM. So, it functioned essentially as a U.S. 80 alternate, since it was roughly the same distance, given the looping route of U.S. 80 in eastern Arizona. But, at Lordsburg, it “bounced” off U.S. 80 northeast to Silver City. (If the present locations of the highways are any indication, it might not have made it all the way to 80 at Lordsburg, since the present day intersection is a couple of miles north of Lordsburg). From Silver City, it was intended to go as a winding mountain road through the Black Range and over Emory Pass, elevation 8228 feet, and then down into the Rio Grande valley to intersect U.S. 85 at Caballo, south of Williamsburg. This connection was not complete in the early 1930s, and yet it was marked as U.S. 180 on both sides of the gap.

So, imagine the surprise of the New Mexico Highway Department in mid-1934, when they were notified by AASHO that U.S. 70 had been rerouted west so that it could be extended to Arizona and, ultimately, California. AASHO informed the department that U.S. 70 would now replace U.S. 380 from Hondo, west of Roswell, through Carrizozo to San Antonio, south of Socorro. Then, it would run concurrent with U.S. 85 south to Caballo, and replace U.S. 180 in its entirety. The NMHD had major issues with this: first, U.S. 380 east of San Antonio had not been improved, and would not be suitable for some time as part of a major cross-country route. Worse than that was the gap in the completed portion of U.S. 180 west of Caballo. There is some angry correspondence from the highway department in late 1934, and they made it clear that they would not mark the changes that AASHO made.

1934 Official New Mexico Highway Map, showing AASHO 1934 routing (blue) and 1935 final decision (green).

Finally, 1935 brought the last major reroutes to U.S. 70. Based on New Mexico’s strong opposition to its initial change to U.S. 70, AASHO agreed to forego the major rerouting west of Hondo, and instead kept 70 on its routing to Alamogordo. Then, it was rerouted west over a newly improved NM 3 to Las Cruces and west along U.S. 80 to Lordsburg. (The segment south to El Paso was incorporated into a newly extended U.S. 54.) From Lordsburg, it replaced the western portion of U.S. 180, which then ceased to exist. The “bounce” portion of U.S. 180 northeast of Lordsburg was then known as NM 180 until the extension of the second U.S. 180 into New Mexico from Texas, when new U.S. 180 replaced U.S. 260. That part of old U.S. 180 is now NM 90 and NM 152. Here, the lack of correspondence with Arizona and California on the route extension makes it unclear whether U.S. 70 was initially intended to terminate at Globe, or Phoenix, or whether its extension west to California was all done at the beginning. In any event, U.S. 70 joined U.S. 60 at Globe, and followed it all the way to Los Angeles by 1935. A couple of years after the extension of 70 to California, that state requested that it be routed along U.S. 99 between Pomona and Beaumont, rather than follow U.S. 60 through Riverside.

Kind of ironically, AASHO correspondence during the 1930s and later express concerns over U.S. routes that shared long concurrencies. A long concurrency with U.S. 60 across New Mexico was rejected for that reason. Nevertheless, from 1935, U.S. 70 never had a piece of pavement to itself west of Globe, Arizona, all the way to Los Angeles. It always shared pavement with U.S. 60 or 99 in that approximately 480 mile stretch. Although…if you were driving westbound on the San Bernardino Freeway after the opening of the Golden State Freeway interchange in 1961, where I-10 exits the San Bernardino to jog south with I-5 to the Santa Monica Freeway, this is what you would have seen:

Photo from GSV of the current sign WB I-10 at I-5, edited to conform to my memory

This is not a historic photo. It’s an edited version of the current sign there, which actually reads U.S. 101 North, but since I can’t download images from my memory, this is a close approximation of what appeared there. The implication from the sign was that U.S. 70 alone occupied the 0.7 mile stretch of the San Bernardino Freeway between the Santa Ana and Golden State Freeways. That would not be true. U.S. 60 still occupied this road, but beginning around 1961, California had deprecated U.S. 60 between downtown L.A. and Pomona by eliminating the shield on interchange signs and putting reassurance markers on poles separate from the I-10/U.S. 70/U.S. 99 sign clusters. The only possible reason for this was in preparation for moving U.S. 60 to the Pomona Freeway upon its later completion. Also, that short piece of freeway was also the original I-110, though that route was never posted. I-110 was eliminated in 1968, and the designation was later resurrected on the Harbor Freeway. Gousha maps from 1964 showed U.S. 70 on uncompleted segments of I-10, but in actuality, all 70 signage was removed that year. A few other U.S. routes lingered after 1964 to temporarily provide a route number for incomplete segments of Interstate highways in California, but U.S. 60 filled that role for I-10. So, U.S. 70 never ran alone in California or west of Globe, Arizona.

The Interstate Highway Era (1964- )

Unlike in many eastern states, Interstate highways in California and the west tended to be constructed over the top of the pre-existing U.S. routes. After freeway construction, there was generally no remaining highway to serve as a continuous link between towns near the freeway. So, California highway officials quickly realized that, without changes to the U.S. highway system, the Interstate highways would in many areas be double or triple marked with U.S. routes that had similar endpoints. For example, the San Bernardino Freeway from downtown Los Angeles to Pomona, was I-10 plus U.S. 60, 70, and 99. The same group of four highways would be marked between Beaumont and Indio. They also had the issue that there were two designations in California (40 and 80) that had both Interstate and U.S. routes associated with them, albeit not along the same roads, which was in conflict with AASHO Interstate Highway numbering criteria. This photo illustrates what motorists along U.S. 70 would have seen around 1961.

I-10 westbound at then-I-15 in Colton. Note the concurrent U.S. and state routes. This is now simply the junction of I-10 and I-215 (I-15 having been rerouted on a new alignment further west). Original photo source unknown.

In 1962, the state notified AASHO that they were undertaking a study to determine where and how to eliminate redundant U.S. route markings. This study culminated in 1963 legislation that completely rewrote California statutes regarding route designations. It was clear that the U.S. 70 designation had no future in California, given that it would virtually never be independent of I-10. So, as part of its initial list of U.S. route changes, California requested that U.S. 70 be truncated to the junction of U.S. 95 in Blythe. This was as far as California could request then, until Arizona could be convinced to remove its portion. In 1969, Arizona rolled back U.S. 70 to Globe. The westernmost segment of U.S. 70 now serves as an alternate route for I-10 traffic between Lordsburg, New Mexico, and Phoenix, though the designation ends well short of Phoenix where traffic then moves to U.S. 60.

The summary of all the routings can be viewed on this map:

Base map is 1950 Rand McNally U.S. map from road atlas for that year.

About Me – Mission Statement

So, being new to this blog thing, I thought it useful to first introduce myself to anyone reading this. My current career consists of being an old prairie dog, living in my little piece of prairie in Pueblo West, Colorado. I retired in 2013 after a career of 35 years or so in the field of environmental management. The last 17 years of that time was spent with a utility (under two corporate owners during that time) that has electric generation and distribution, along with gas distribution operations, across a number of states in the Mountain West and Midwest.

I won’t name the company, but since the reader could probably infer which company it is, and I intend to report and comment on environmental issues, I will use my expertise and experience working in this field to inform my work. No one should infer from anything I write that my employer’s operations were not in compliance with applicable requirements. In fact, the company did strive to maintain full compliance with regulations governing its operations. My job principally was maintaining this compliance.

Soooo…. A mission statement. The reader will probably see two topics here. The first is the aforementioned topic of the environment.  You will find that I have an abiding concern about degradation of our environment. Although the U.S. has implemented major protection programs that have resulted in significant improvement in the quality of our air and water, there continues to be major pressure on these media. Congress frequently tries to tie the hands of the U.S. Environmental Protection Agency (EPA), and our newly elected Congress seems to think it has a mandate to significantly roll back the protections we already have. Also, sorry to disappoint the climate skeptics out there, but I have come to accept that human activities are resulting in alteration of our climate. There is something about 97 percent of people practicing in a field agreeing that I find convincing. As a scientist (did I forget to mention that above?), I am offended when obvious science illiterates are given positions of power over science agencies.

The other, mostly unrelated topic I intend to post on is transportation. Specifically, roads. I have a lifelong interest in highways, how they’re constructed, what they’re numbered as, how they’re signed, and where they go. Later in life, I have become interested in “clinching” major highways, i.e., driving them from one end to the other (not necessarily at the same time). Others with these types of interests like to clinch counties, but I haven’t gotten that bug.