The Oregon-California Trail carried more than 100,000 settlers west over the prairies of the future state of Kansas in the mid-1800s. Pioneers and Pony Express riders crossed the Big Blue River at Independence Crossing or at Frank Marshall's ferry near present-day Marysville. In 1846, members of the Donner Party discovered and named Alcove Spring, now one of 20 county sites listed in the National Register of Historic Places. The Kansas Territorial...