2005. National Atlas of the United States. This polygon shapefile portrays the time zones of the United States, Puerto Rico, and the U.S. Virgin Islands. Also included are the Greenwich Mean... National Atlas of the United States.
2005. National Atlas of the United States. The Topographic and Bathymetric Shaded Relief of North America map layer shows depth and elevation ranges using colors, with relief enhanced by sha... National Atlas of the United States.
1910. Iowa State College. Department of Civil Engineering. Date from record from seemingly related bulletin (Bulletin, Engineering experiment station, no. 32). 45 x 45 centimeters Scale approximately 1:25,0... The Collegé (Ames, Iowa).