Several thousand Native Americans still occupied the basin when Lewis and Clark passed just south of the Reach in 1805. Fur trading and military posts gave rise to the initial settlement of the area. The ferry crossing on the White Bluffs road, a probable Indian trail, was the hub of transportation, and the scene of many cattle drives and wild horse roundups for the region, by 1860. Remnants of the road are visible in parts of the Monument Steam boats and wagons met here to transport supplies and gold between the coast and mines in British Columbia, Montana and Idaho.
About 1870 scattered homesteads appeared along the river banks, struggling to farm and raise stock. The only standing structure from this time period is a log cabin built about 1894, at the ferry landing, which served as a blacksmith shop and possible living quartrers. Promises of irrigation just after 1900 spurred spirits and growth in White Bluffs, Hanford and Wahluke settlements. The Hanford Ditch built in 1907 carried water from pumping stations along the river to anxious farmers. Several pumping stations remain in the Monument today. The arrival of the spur line of the Northern Pacific Railroad to Hanford in 1913 brought more families. Settlement continued until the Depression in the 1930's but times were tough.