Having lived much of my life in New Mexico, I often find myself wondering why there are so many places in the state about which I have read or heard very little or nothing. One such place is the Gilman Tunnels in the Jemez National Recreation Area, roughly five miles northwest of the intersection of Highway 4 and Highway 485. I read about the tunnels while researching the Jemez Mountains, and they certainly are impressive. I was dwarfed by the height of the massive granite jumbles and stacks out of which they were blasted and cut. The New Mexico Bureau of Geology and Mineral Resources division of New Mexico Tech (New Mexico Institute of Mining and Technology) in Socorro provides both historical and scientific data on the area.
"Two narrow and unusually high tunnels were cut through Precambrian granite in the 1920s to facilitate passage of logging trains through this particularly rugged and constricted section of Guadalupe Canyon, known as the Guadalupe Box. Logs that were harvested in the western Jemez Mountains in the 1920s were taken by narrow-gauge railroad to a sawmill in Bernalillo. The tunnels were enlarged in the 1930s to accommodate logging trucks." (geoinfo.nmt.edu). Not only was I impressed by the size of the tunnels and the colossal rock of the area, but by the work that must have been required to find a suitable area and survey it in the first place, and then to blast and clear rock, without having the luxury of fossil fuels and trucks to haul materials. The original road to the area was probably sketchy to say the least. Like many of the tunnels in the Sierra Nevada Mountains in California, was well as other places around the world, human power made the project possible. The image below is of the first tunnel you would approach driving from Jemez Springs on Highway 485.
Two closeups of the tunnel ceilings and walls
I insert this detail of the southern part of the Guadalupe Box detail as a demonstration of the massive rock and complexity of it. Some of the rock sheets seem to be shaggy and ready to slough off at any time. Notice a cave forming in the center of the bottom third of the photograph.
shooting north in the Guadalupe Box
"The lower stretch of the Guadalupe River canyon exposes a thick section, including Permian redbeds of the Yeso Formation, Glorieta sandstone, and Triassic Moenkopi and Chinle strata, capped by thick exposures of Bandelier tuff." (geoinfo.nmt.edu). I can guarantee you my memory won't hold all this information, but the photograph, again, demonstrates the incredible and complicated (not to mention beautiful) geologic history of the area.
As the seasons begin to change and move toward the equinox next month, I hope you are able to get out and take advantage of the special light. The trip to the Gilman Tunnels is well worth your time. Although Highway 485 is the former railway grade and bed, it is well maintained and an easy drive. If you continue further into the Guadalupe Box region, the road which carries the number 376, requires a four-wheel drive vehicle.
My thanks to Tim A., Connie T., TTT, Barbara F. R., Jean & Sam, Marilyn G., Catherine, and Steve for commenting this week.
until next Monday,
a passion for the image©