After the sheriff drowned in the Missouri River, McKenzie was appointed as the sheriff of Burleigh County, North Dakota. He served as sheriff from 1874 to 1886, being elected five times. During this time he was also a deputy U.S. marshal.
Following the tragic event involving the sheriff in the Missouri River, McKenzie became the law enforcement officer for Burleigh County, North Dakota. He served from 1874 to 1886 and was re-elected five times. During this period, he also worked as a deputy U.S. marshal.