Koehler was born in Sparta, Wisconsin on March 6, 1944, to parents Irene and Lyle Koehler Sr.[1] He attended Black River Falls High School for two years and finished at Sparta High School before enrolling at the University of Wisconsin–La Crosse.
"[4] Upon completing his Master's degree, Koehler began working as the director of tutorial and referral services at the University of Cincinnati.
[5] During the summer of 1973, Koehler began his research in various New England courthouses reading arrest records of 17th-century Colonial women.
[6] His work accumulated into his first book, A Search for Power: The 'Weaker Sex' in Seventeenth Century New England, which was a finalist for the 1981 Pulitzer Prize for History.
[7] Following this, Koehler left Cincinnati and became an editor and technical writer at New Mexico State University.