Dern developed a reputation as an efficient manager and innovator, developing a vacuum slime-filter process and the Holt-Dern roasting process, the latter process utilized by various mining concerns both in the United States and abroad. In the wake of the Consolidated Mercur's shutdown in 1913, Dern managed mining concerns in other parts of Utah, including Park City's famous Ontario Mine (1912-1915); the Tintic Milling Co., in partnership with Jesse Knight (1915-1919); and the famous Emma Mine in the Alta Mining District (1919-1920). Dern was also involved in a wide variety of other Utah business concerns; including ranching, dairying, public utilities, and banking Dern's rise as an important Utah politician commenced with his election in 1914 as a Democrat to the Utah State Senate representing Salt Lake County. Serving in this body for two terms (1915-1923), he became known as a progressive politician promoting various reform measures, most notably Utah's first workmans compensation act in 1917. Despite being a non-Mormon and a Democrat in a state which was predominately Mormon with strong Republic tendencies, Dern got along well, politically. He was personable and empathetic, willing to listen and respond to all points of view. This served him well in his election to the office of Utah governor in 1924. He was successful in defeating his Republican, Mormon opponent, the incumbent governor, Charles R. Mabey, during a year of Republican ascendancy.