The Spoon River is a 147-mile-long tributary of the Illinois River in west-central Illinois in the United States. The river drains largely agricultural prairie country between Peoria and Galesburg. The river is noted for giving its name to the fictional Illinois town in the 1915 poetry work Spoon River Anthology by Edgar Lee Masters, who was from Lewistown, which is …The Spoon River is a 147-mile-long tributary of the Illinois River in west-central Illinois in the United States. The river drains largely agricultural prairie country between Peoria and Galesburg. The river is noted for giving its name to the fictional Illinois town in the 1915 poetry work Spoon River Anthology by Edgar Lee Masters, who was from Lewistown, which is near the river.