Pioneer Monument Donner Memorial State Park, Truckee: The Pioneer Monument was erected in honor of all who made the difficult trek across the western plains and mountains to reach California during the 1840s. Constructed near the site of the cabins that gave shelter to the Donner Party, work on the monument began in 1901. On June 6, 1918 in a ceremony that included Donner Party survivors, the Native Sons of the Golden West donated the completed monument and eleven (11) surrounding acres to the State of California.