milestone vs range pole

milestone

noun
  • A stone milepost (or by extension in other materials), one of a series of numbered markers placed along a road at regular intervals, typically at the side of the road or in a median. 

  • An important event in a person's life or career, in the history of a nation, in the life of some project, etc. 

verb
  • To plan out a project as a series of major steps. 

  • To place milestones along (a road, etc.). 

range pole

noun
  • A rod or pole, marked with alternating red and white bands, used by surveyors for sighting 

How often have the words milestone and range pole occurred in a corpus of books? (source: Google Ngram Viewer )