From 1925 to 1932 Kassler continued his studies while living at various times in New Mexico, Europe, and North Africa. While in France, he apprenticed himself to a well-known fresco painter. After moving to Los Angeles in 1933, he painted the two largest frescoes done under the WPA. The Bison Hunt at the Central Library in downtown L.A. was destroyed by weather damage. The other, Pastoral California, at Plummer Auditorium in Fullerton, in Orange County, was restored in 1997, after spending almost 60 years hidden from view. It was whitewashed in 1938, just four years after Kassler completed it. After the WPA, Kassler taught at Chouinard Art Institute and later worked as a designer in the aerospace industry.