There are two stories on how Cassia County got its name. One says it was named after a French explorer named DeCassia. The other says it was named after the Cassia plant that grows along the banks of the Snake River.
In 1905, David E. Burley, a Union Pacific Railroad passenger agent, conceived an idea of building a city along the Snake River where the railroad passed. Since Mr. Burley's work necessitated travel throughout the Midwestern United States, he influenced many farmers to migrate to this area.
Mr. Burley, along with. B. Perrine, established the town "Commerce." Its name was later changed to Burley where the county seat was subsequently moved in 1919 by public vote.
In the spring of 1984, because of the harsh winter and the early thaw, the Oakley Dam nearly burst. Had that taken place, it would have flooded the Oakley Valley all the way to the Snake River. The dry beds of Goose Creek, wherein lies Burley, also would have been flooded. However, it was avoided by the persistence of residents building a 30 mile canal to the Snake River in just a matter of days.