The Arrow Rock area was where the historic Santa Fe Trail crossed which longest river in North America?
Arrow Rock Historic District Arrow Rock Historic District is a National Historic Landmark District encompassing the village of Arrow Rock, Missouri and the adjacent Arrow Rock State Historic Site. The Arrow Rock area was where the historic Santa Fe Trail crossed the Missouri River, and was thus a key stopping point during the settlement of the American West. The 260 acre historic district was declared a National Historic Landmark in 1963.
Sangamon River The Sangamon River is a principal tributary of the Illinois River, approximately 246 mi long, in central Illinois in the United States. It drains a mostly rural agricultural area between Peoria and Springfield. The river is associated with the early career of Abraham Lincoln and played an important role in the early white settlement of Illinois, when the area around was known as the "Sangamon River Country". The section of the Sangamon River that flows through Robert Allerton Park near Monticello was named a National Natural Landmark in 1971.