Heart of America DHIA was formed in 1995 with the merger of six state DHIA's. Our main office is in Lincoln, Nebraska; with field staff in Milbank, South Dakota and Wagoner, Oklahoma. In one form or another, DHIA has been in the area since the early 1900's. We primarily serve dairymen from North Dakota, South Dakota, Nebraska, Kansas, Oklahoma, Arkansas, and parts of Missouri, Iowa, and Colorado.