He studied at Augustana College in Sioux Falls, South Dakota where he earned a B.A. Degree and then earned an M.F.A. at the University of Iowa.
As a painter, he began working in representational style in oil and focusing on Pop Art sports imagery subjects. But during a 1967 trip to Colorado with his wife, Dorene, he took up acrylic painting and this combined with an influential trip to England led him to a "more structured composition. . . According to Eisentrager, all painting---regardless of style or imagery---is geomeric in nature because it involves the manipulation of the picture lane. The artist likened his own approach to that of a scientist: the process is difficult but 'it's got to be done.' "
He has exhibited with the Mid-America exhibitions in Kansas City and with the Mid-West Biennial at the Joslyn Museum in Omaha.
“My work is about structure, composition, proportion, balance and equilibrium. These are not emotions, but they interest me.” Although Eisentrager began his art career with representational painting, he is best known for what he calls his “structuralist” works. These paintings are influenced by shape, by geometry, by mathematics. Because of this he connected largely with the anti-Expressionist tradition. Eisentrager studied at Augustana College in South Dakota, and received his M.F.A. at the University of Iowa. He was a Professor of Art at the University of Nebraska, and exhibited in Kansas City and at the Joslyn Museum of Art in Omaha, Nebraska.