Hatcheries account for up to 750,000 rainbow trout, 450,000 yearling kokanee and 3 million kokanee fry being released into Lake Roosevelt annually.

Rainbow trout production begins at WDFW's Spokane Hatchery. From here, about 1.1 million eggs are transferred to the Spokane Tribal Hatchery and reared to about 2 inches in length. Half the fish reared at the tribal hatchery are eventually transferred to WDFW's Sherman Creek Hatchery for further rearing. The trout are later transferred to the net pens for the final rearing step.

At WDFW's Colville Hatchery, 75,000 redband trout are reared from local stocks originating from upper Columbia River tributaries. These trout are genetically linked to those found in the Kettle River tributary.

About 4 million kokanee eggs are also sent to the Spokane Tribal Hatchery for rearing. Two stocks of eggs are used, a coastal stock from Lake Whatcom, WA and an up-river stock from British Columbia. After reaching fry or post-smolt size, they are released into the lake. Kokanee eggs from Canada are preferred because they are native to the upper Columbia system.