Post Offices in Boulder, Colorado, United States SearchSearch SearchSearch View: Grid 1View: Grid 2View: Grid 3View: Grid 4View: Grid 5View: List Boulder Post Office No Reviews Favorite Fax: (303) 786-8756Phone: (303) 938-3704Retail Hours High Mar Post Office No Reviews Favorite Fax: (303) 499-4790Phone: (303) 938-3730Retail Hours Valmont Post Office No Reviews Favorite Fax: (303) 245-6486Phone: (720) 564-6400Retail Hours