From Michigan County Atlas
New York State native and Civil War veteran Oscar F. Bentley built a sawmill here in 1886. His business was taken over by his son, Frank E. Bentley, the first postmaster of BENTLEY in 1887 (the spelling corrected to Bentley in 1909). Population 400 in 1918, this was a manufacturing center with saw and shingle mills, a cheese factory, hoop factory, hotels, bank, drug store, doctor, and bakery.
From Michigan Place Names
Bay County: founded by Oscar F. Bentley who was born in Monroe N.Y in 1833. He had served three years in the Minnesota Volunteer Cavalry in the Civil war before coming here and building a sawmill in 1886, in which business he was succeeded by his son, Frank E. Bentley, who became the first postmaster of Bentley on Feb. 26, 1887, with the corrected to Bentley on June 16, 1909 [MS. Causley, Jr. PO Archives]