Herbert L. Zimmermann (sometimes spelled Zimmerman) was born on October 28, 1888 in Princeton, Minnesota to Irving and Josephine Zimmermann (née Wentworth). He had two siblings, Bruno Zimmermann and Wanda Zimmermann. Herbert Zimmermann attended public schools in Minnesota and by 1910 worked as an assistant at the Security State Bank. In 1912, he married Hulda Buirge. In 1916, Zimmermann moved to Minneapolis to work for Minnesota’s federal reserve bank and later, in 1922, he transferred to the Helena branch to work as an assistant federal reserve agent and auditor. In 1926, he was promoted to cashier, and he maintained that position until his death in 1932. Herbert L. and Hulda often wrote to Josephine and Wanda Zimmermann, who lived together in Minnesota (Irving Zimmermann died in September, 1893), and described their life in Helena. They often spoke of camping, fishing, hunting, vacationing, house searching, weather, illness, local Helena news, and other topics.

On April 16, 1932, Herbert Zimmermann died in a boating accident during a fishing trip on Meadow Lake in Madison County. Dr. William M. Copenhaver and Mr. R. H. Saum, who were with him, also died in the accident. Zimmermann was buried in Forestvale Cemetery in Helena, Montana.