The History of Steamboat Rock Dam

Prepared by Maria L. Schmid, Architectural Historian

Mill and dam circa early 1900s, view from the river downstream. Source: Steamboat Rock Historical Society Archives.

The dam at Steamboat Rock is an important part of the community’s history.  In 1855, shortly after the town of Steamboat Rock was established, a sawmill was built on the Iowa River by Isaac Lesh, Charles Boyle, and Samuel G. Higginbotham. The sawmill produced the lumber for the businesses and homes in Steamboat Rock.  In 1857, S. F. Lathorp acquired the sawmill and dam and constructed a three-story gristmill at the location.  The mill had the processing capacity for 125 barrels of flour a day.
 
The original dam was built of wood planks with rock rubble placed beneath as a structural stabilizer. The mill and the dam went through changes and repairs over the years as grain production increased. A mill house was located west of the gristmill.  A fire at the mill in November of 1910 destroyed the building and, after fifty-three years of continuous operation, the mill was closed. The original wood dam deteriorated from age and was washed away by the river.
 
For a brief time around 1912, a plan was developed to generate electricity at the old mill’s location and a powerhouse was constructed over the mill’s stone foundation.  However, the idea never took off, and the hydroelectric plant was not completed.  The old dam again fell into disrepair. 
 
Following the Great Depression, federal work relief projects under the Works Progress Administration (WPA) aimed to alleviate unemployment and provide economic relief. Many dams were built on Iowa Rivers during the 1930s, in addition to parks, roads, and other infrastructure.  The WPA contributed $7,800 towards completion of a new concrete dam at the location of the old structure at Steamboat Rock, and the town of Steamboat Rock provided $3,200.  Fifty men worked on the project for approximately three months under the supervision of Ernest Welden of Welden Brothers, an Iowa Falls company.  Fifteen men from the Civilian Conservation Corps camp in Eldora also helped to build the dam.
 
The current dam at Steamboat Rock dates to 1941, though features remain from the 1912 powerhouse construction and the earlier 19th century mill, for example, the concrete foundation on the river’s west bank and the old gristmill’s stone foundation underneath.  An earthen dike on the east bank is likely a remnant from the original structure.  A shelter cabin was added in 1948 above the powerhouse foundation and the west abutment was reconstructed in 1967. The Steamboat Rock Dam site is a back-drop for development in different eras. The dam has left a mark as a testament to human use and management of the Iowa River in the town of Steamboat Rock.

1892 Plat Map of Hardin County showing the Steamboat Rock Mill and Dam. Source: North West Publishing Co., F. Bourquin, and Balliet & Volk, Library of Congress.