Some 70,000 people made the trek across the Great Plans to Zion between 1846 to 1869, when the First transcontinental railroad was completed, and sporadically until the 20th century.
Many died in unnamed places along the way. Some had their death recorded in a journal entry "on the Plains in Wyoming".
The Death Place Names drop-down menu has "At Sea", so is it possible to add "On the Plains" with additional location info after a comma, i.e.; On the Plains, in Wyoming Territory.