Jenson Tunnel or “Backbone Tunnel” is not only the state’s first and only railroad tunnel it is the only one built in a foreign nation. The tunnel was bore out between 1885 and 1886 in the Choctaw Nation of Eastern Oklahoma. In 1871 operation of the “Katy” (Missouri, Kansas, and Texas lines) and the Atlantic and Pacific railways (Frisco railroad) began. But for the next 15 years there wasn’t a railroad building in Indian Territory. The lines spread out to surrounding states but there were gaps in the railway coverage. The Fort Smith and Southern Railway was purchased by the Frisco Railroad in 1886. They laid lines from Fort Smith Arkansas across the Choctaw Nation down to Paris Texas. The “Backbone Tunnel” was key to the lines since it was completed in early 1887 allowing the railway to open up for service.
The tunnel today still hasn’t changed from the early days of Indian territory. It was dug through solid rock and is 1,180 feet long. The tunnel has an average width of 14 feet, but it reaches 20 feet in some places. The average height above the rail is 20 feet but it reaches 24.7 feet at one point. The tunnel has 629 feet of interior that is unprotected rock that requires no arching. Almost 384 feet of stone walls with a brick natural arch were used at both ends. There are 62 feet of stone walls with a timber arch. The remainder of the project used 118 feet of timber posts and arches.
The tunnel was listed in the National Registry of Historic Places in 1976 stating that “The construction alone, especially in this day of steel and pre-cast concrete, is noteworthy and therefore deserves preservation. Also worth noting: Jenson continues to serve a state that was not born until nearly a quarter-century until after completed.”
Jenson Tunnel is located northeast of Cameron off of Highway 112 on private property.
I overheard someone talking about a railroad tunnel today and it just clicked. I haven’t thought about it in years. Actually, as a teenager a group of us hiked in there to check it out. I remember the fallen leaves covered in dew were slick going down that steep incline. We explored the tunnel and ran out of there when we heard the train coming. And just a side note for my mom, I had already graduated so you can’t ground me now. The statute of limitations is up. How could I have not thought about this in so many years? It is amazing how many unique things that we have right here in Eastern Oklahoma.
*National Registry of Historic Places Nomination form 1975/1976.
