"New Mexico has 25,000 miles of unpaved roads. Dirt, sand, clay, stone, and caliche constitute up to 75 percent of our roads." https://www.newmexicomagazine.org/blog/post/100th-anniversar...
"Santa Fe has a higher percentage of dirt roads than any other state capital in the nation. Unless they are well graded and graveled, avoid these unpaved roads when they are wet. The soil contains a lot of caliche, or clay, which gets very slick when mixed with water. During winter storms roads may be shut down entirely." - https://archive.nytimes.com/www.nytimes.com/fodors/top/featu...
With Google Maps, the dirt road closest to the center of town that I found is Del Norte Lane, at about 1/2 mile, with more dirt roads just north of it.
Santa Fe also has a lot of multi-million dollar homes on dirt roads.
Santa Fe is a special place, and not indicative of "average".
Santa Fe is weird this way because it's so old. Santa Fe is old by "old European city" standards; it's 166 years older than the United States. The roads downtown were originally burro paths.
It's also funny that the article calls New Mexico a "warm place" considering I had to plow a 2-foot accumulation of snow off my driveway a couple weeks ago. New Mexico's climate is neither warm nor cold but diverse.