Lewiston, Utah, is located in the geographic center of Cache Valley, twenty miles northwest of Logan and ten miles south of Preston, Idaho. The town occupies a triangularly shaped land area of approximately 24 square miles, with a base along the Utah-Idaho state boundary in the north, and extends southward between the Bear River on the west and the Cub River on the east to a point where the two streams join in the south. The area is almost entirely flat and contains some of the most productive agricultural land in the state.

Lewiston has always been an agricultural community. The dairying and livestock industries are predominant, and most crops are grown to support them. Some acreage is devoted to supplying vegetables to canneries in the area, but wheat, barley, and alfalfa are the major crops produced. Sugar beets, an important crop for many years, declined in importance after the town's sugar factory closed in 1972. Many residents supplement their farm incomes by working in local factories or through other non-farm occupations.