The Decorah Fish Hatchery is located two miles south of Decorah in Winneshiek County. The area is extremely popular among visitors to this scenic region of Iowa. The picturesque limestone office and residence date back to the 1930s as a project of the Civilian Conservation Corps.

The tract, originally known as the Siewers Springs Bass Hatchery, was constructed on a 17 acre plot of land purchased from the John Hjelle family in 1931 for $7,500. The original emphasis at the facility was smallmouth bass culture, taking advantage of a dependable water supply from Siewers Spring, Iowa's second largest spring. The initial investment for construction of buildings, ponds, and raceways totaled $25,000. Over the years the hatchery became important for the culture of rainbow and brown trout, plus some occasional use with cool-water and warm-water species as well.

Although the stone buildings still stood solid, by the mid 1980s serious problems were hampering the use of the Decorah facility for fish production. Problems with both the antiquated water supply system and with water quality were evident. Although the quantity of water from Siewers Spring had always been dependable, the water erupting from the spring was contaminated periodically by heavy silt loads and high nitrogen gas. These situations combined with widely fluctuating dissolved oxygen levels, made for an unreliable environment for fish production.

Taking advantage of moneys available from Sports Fish Restoration, the fisheries bureau of the Iowa DNR decided to renovate the Decorah Hatchery. Approximately 2.4 million dollars were spent to upgrade the facility. The "new" hatchery went on line in 1989 as an extraordinary facility capable of compensating for the inferior water which at times emerges from Siewers Spring, the sole water supply for the hatchery. Much of the heavy silt load is now short-circuited before it reaches the raceways and ponds of the hatchery complex. Oxygen is added to the hatchery water as needed and excess levels of nitrogen gas are reduced.

Additional modifications and improvements continue at the hatchery, many aimed at making it better understood and more accessible to the large numbers of hatchery visitors. Signs are spread throughout the hatchery grounds to offer an informal tour and answer many of the most-asked questions. A visitor center, nestled in a gazebo within the main entrance of the hatchery, offers maps and literature covering the hatchery and Iowa trout program in general. Group tours can be scheduled by calling the hatchery during regular business hours.

The Decorah Hatchery is responsible for the stocking of seventeen streams in the counties of Winneshiek, Allamakee, Howard, and Mitchell. Stocking numbers for the season total approximately 120,000 catchable size rainbow and brown trout, plus a few thousand catchable brook. These fish are annually requested by fisheries management staff to meet the put-and-take need in these streams. Some streams are stocked with rainbows entirely, some with browns entirely, and some with varying percentages of the two. Most stocking runs are announced daily, although several of the brown-only streams are never announced. Most of the streams are stocked once each week, although this also varies depending on the use of the streams.

The Decorah Hatchery is charged with stocking some of the most pristine streams available in Iowa and are in use virtually every day of the year. Stocking is done from April through October on most of the streams, and continue on through November on some of the larger streams in state-owned areas. A few of the streams must have stocking trips interrupted during the hottest weeks of the summer.

In addition to the stream stocking, Decorah Hatchery is also responsible for the stocking of several thousand trout into Blue Pit in Mason City in Cerro Gordo county during the winter months for ice fishing.