Question: The Mars Society is an American worldwide volunteer-driven space-advocacy non-profit organization, inspired by "The Case for Mars" conferences which were hosted by The Mars Underground at the University of Colorado Boulder, a public research university located in Boulder, Colorado, in which country?
Sentence (from "University of Colorado Boulder"): The University of Colorado Boulder (commonly referred to as CU or Colorado) is a public research university located in Boulder, Colorado, United States.
Relevant evidence: Yes