Oklahoma interstates that were built as at-grade expressways

[Brian556]

The rail crossing was at https://goo.gl/maps/cMKJ9Zo25fq

I forgot to include a link to Historic Aerials, but it's at https://www.historicaerials.com/location/34.64461259658542/-98.38849067687988/1970/16

That shows the rail crossing for the Fort Sill Spur. It shows that the mainline crossing south of Cache Rd was already grade separated. Bobby5280 stated that the mainline crossing was not grade separated until around 1980

[capt.ron]

When our family drove US-66 from St Louis to Flagstaff AZ in 1968, we ran into several intervals where I-44 and I-40 would suddenly "end" and we had a traffic light for an at grade intersection.  When we drove it again in 1970, many of those intervals were gone due to more completion of the Interstate Highway System. Maps back then struggled to keep up.  I remember my father stopping at a gas station in Claremore to get a more up to date state highway map due to the constant updates on US-66.

I bet the 1960s were an exciting time to be a road enthusiast. Interstates were being built rapidly and many new sections opened each year. I often daydream about living in that era. I wasn't born until '73 so I missed out on most of the rapid construction of the interstate system.

I was born in 1971 so I caught the tail end of the growing presence of the Interstate Highways. Speaking about I-40, it wasn't until maybe 1975 or so when I began to pay attention to the outside surroundings as we drove from our home (at the time) in California to my mother's parents in Arkansas, and to my dad's parents in Georgia.
I remember I-40 being complete in California (completed in early 1973 but my memory only goes back to 1975-76). Crossing into Arizona, I-40 stopped just southwest of Kingman. I remember the stretch of US 66 from Kingman to Seligman. On our way back to California (late 1970's) my dad pulled off of I-40 / US 66 westbound at the Painted Desert rest area and got a couple of pictures next to the red rocks. I remember cutting through Winslow and Holbrook... marveling at the Wigwam.
I remember I-40 in New Mexico having TONS of median crossings...probably due to the fact I-40 at that time had numerous at-grades for ranch access and so on during that time. The area just east of Albuquerque (Carnuel to Tijeras) was a little foggy to me. 4 lanes but it was just expressway. Then that LONNNNG  and rather straight stretch east of Cline's Corners to just west of Santa Rosa.
I don't remember Tucumcari that much... I may have been napping in the car at the time. Then the 2 lane section of 66 from Tucumcari to San Jon. I vaguely remember that. Then came Texas. I always remember going through McLean with its brick main st. Only part of Oklahoma I remember is from the TX/OK state line to OKC. After that, I may have been napping again, lol.