He played in 887 Major League Baseball games for the Minnesota Twins and Chicago Cubs, primarily as a catcher, over 11 seasons (1966; 1968–77).

Mitterwald played for skippers Billy Martin with the 1969 Twins and Jim Marshall with the Cubs from 1974 and 1976.

He was traded from the Twins to the Cubs for Randy Hundley at the Winter Meetings on December 6, 1973.

He coached female pro pitcher Ila Borders while managing the Dukes.

This biographical article relating to an American baseball catcher born in the 1940s is a stub.