Daniel R. Euwer was born in 1857 in Pennsylvania to Daniel and Martha (Bryant) Euwer. He followed his father, who was born in Ireland, into the lumber business. The name Euwer was actually Yourd in Ireland.
In addition to Euwer and brothers lumber dealers, he was the Director of the Iron City National Bank of Pittsburgh.
His siblings included: Hayes Euwer, Jennie Euwer, Beckie Euwer, and Joseph Euwer. Additionally, he was the brother-in-law of the renowned scientist and author Henry Grier Bryant who associated with him in the lumber business owning large tracts of timberland in northwestern Pennsylvania.