In answer to both George and Jimmy's questions.
The first picture is on the climb out of Carbon Junction toward Chama, about where the new hospital is.
The next two are on the Farmington branch not too far south of Carbon Junction. In answer to George's question, the rail has been removed so that they can dig out and replace a soft fill. Both the slip out on the mainline shown in the first picture and the work to replace the soft fill on the Farmington branch were the result of a very wet monsoon season. The Farminton branch was out of service for a week or two until the rail could be relaid.
The forth picture is at Cumbres. If I remember correctly the crew was replacing rail and switch ties around the crossover in the middle of the long siding.
JBWX