Emma Russell was raised in Illinois and attended Southern Illinois Normal College (now Southern Illinois University). After receiving her teaching certificate in 1883, she came to Idaho to look for a teaching position. Emma started working as a tutor and governess for a family near Salmon, Idaho and then spent two years teaching in small schools in the Lemhi Valley. A pianist, she was also in demand at local country dances and it was at one of these dances she met her husband, Thomas Yearian, a fiddler and young cattle rancher. The two were married in 1889.

In 1902, after having six children, Emma decided to go into the sheep business. It was an unpopular choice at the time, as the Lemhi and Salmon River valleys had always been cattle country. Despite opposition, however, her venture was a success. By 1910, the family moved out of their old log cabin into a fine six-bedroom stone house, complete with electric lights and indoor plumbing. By the 1930s, her sheep operation had spread over 2,500 acres of range, with 5,000 sheep.

Emma's forceful personality led her to politics in 1930. She ran for the Idaho House of Representatives and became the first woman to represent Lemhi County. Her re-election effort, however, was swamped by the Democratic landslide in the next election.

She continued her sheep operation until very late in her life, despite a steady decline in U.S. demand for wool and lamb.