A Memoir of One Woman’s Life-Long Love Affair Flying a Vintage 1941 Piper J-3 Cub Aircraft in Minnesota’s Famed Arrowhead Region Kathryn Krotz-Fin’s story is also a heartfelt tribute to her father Clarence J. Krotz, a former Army Air Force Bomber Pilot in WWII who created the first official airport for Grand Marais in 1948.