The firm originated in Fergus Falls in 1883, when William L. Parsons and James A. Brown became partners. They ran a very successful practice, which became known as Parsons & Brown. William L. Parsons was appointed judge of the 7th Judicial District in 1914. James A. Brown continued to practice law on his own until 1920, when he and Roger L. Dell joined forces.
In 1929, James A. Brown passed away, Roger L. Dell partnered with Chester Rosengren, and the firm became known as Dell & Rosengren. In 1948, Gerald S. Rufer joined the partnership, and it soon became Dell, Rosengren & Rufer. Roger Dell was appointed chief justice of the Minnesota Supreme Court in 1953, and the firm became Rosengren & Rufer. In 1953, Robert O. Blatti joined the firm of Rosengren & Rufer, and in 1955, it became known as Rosengren, Rufer & Blatti. In 1958, Richard Hefte joined the firm and partnered with Rufer and Blatti, and the firm became known as Rosengren, Rufer, Blatti & Hefte.
In 1960, Richard L. Pemberton joined the firm, as did James L. Schulze in 1965. Chester Rosengren, like Parsons before him, was appointed judge of the 7th Judicial District in 1965. A few years later, the firm became known as the law firm of Rosengren, Rufer, Blatti, Hefte & Pemberton, and this name continued until 1968, when it was changed to Rufer, Blatti, Hefte, Pemberton & Schulze. In 1968, Oscar J. Sorlie joined the firm. In 1970, Robert O. Blatti passed away, and the firm became Rufer, Hefte, Pemberton & Schulze.
In 1974, the firm hired another attorney, Gerald Rufer's son, Stephen F. Rufer. In the years to come, this would become a family tradition—three generations of Rufers have worked with the same firm. Over the next ten years, the firm added H. Morrison Kershner, Robert W. Bigwood and Michael T. Rengel.
Known as Pemberton, Sorlie, Rufer & Kershner, the firm continued to grow at an increasing rate by hiring Kent D. Mattson in 1993, and Kristi A. Hastings in 2001, followed by Nicholas J. Heydt, Katrina I. Wass, Chad R. Felstul, Joshua M. Heggem, Sarah C. Duffy, and Kendra E. Olson, all at the Fergus Falls location.