Both the Oregon and California Trails, with cutoffs and alternates, have left a physical and chronological mark on the borderlands of Utah, Idaho, Wyoming and Nevada where- hope to God - I'll be walking again soon. Those were the interstates of the times though. Wagon tracks criss-cross the real West. In some places the country is sensitive, despite its best efforts at putting on a contrary face. Any place where more than 100 knife-wheeled wagons passed or re-passed in a season tells that tale to educated or experienced eyes.This map from Chaco Roads, John Kantner
Any time spent walking arid western deserts qualifies as class time, although some preconditions have to be met. The first is you have to think about how you would get a wagon across the country you're looking at. The second is you have to be looking at country not already populated by dirt, gravel and tarmacked roads - not so common these days. The third is you have to know where things are or were. Rivers, ravines, and ranges need crossing if there are between point A and B. Box canyons with no water, pasture or ore don't get many visits. Traffic lines are actually fairly predictable if you ponder on it for a while.
There are some historical exceptions - at least one that I know of - that maybe work to prove the rule. That exception would be the Anasazi roads around Chaco Canyon around the 4-corner borderlands in northern Arizona and southern Colorado. For reasons only guessed at the Anasazi built straight directional roads, sometimes in pairs only yards apart, through redrock country. They carved steps on cliff faces to keep to a true direction. From the time they stopped being used in the 12th century or so, until just some decades ago, the Anasazi roads were invisible to the logic of travel.
A satellite filming vegetation in the infrared spectrum prompted the first official investigators. Amazingly straight lines appeared in the desert where such lines are unnatural. They had to be vegetation as only living matter would show in that hue of red. When human eyes reached the spot they found curb-like structures of laid stone 30 feet wide that trapped what little moisture there was in parallel troughs. More water, more plants. Stone roads in the desert, hundreds of years old. Some straight as a compass reading where no known compasses existed. Straight in defiance of topography and good sense.
The Anasazi roads are still a puzzle. The current take is that they are religious in nature, rather than functional. I don't know. Many of Chaco's mysteries are put on the altar of ancient religion. I know a lot of people around here pray about roads.
