What we know
Post office 1908-1915 'in a country store' (Place Names of Colorado), on Scott's Leavenworth & Pike's Peak Express line.
Where it was
'Hargisville 1908': Scott, Historic Trail Map of the Denver 1x2 Quadrangle (USGS I-2639, 1999, S-0106), symbol read from the reprojected sheet (good to a few hundred feet). Place Names of Colorado: Sec. 20, T7S R62W, 'Rural Post Office 1908-1915. 8 mi NE of Kiowa. In a country store.'; this point is 0.37 mile from that section's center.
Read from Glenn R. Scott's USGS historic trail map of 1999 and confirmed by a second, independent source.
Sources
Sources are named in the text above. Numbers such as S-0080 refer to our source list. Most newspaper quotations were read in the Colorado Historic Newspapers Collection. Long quotations from recent books are shortened here.