Prior to arriving at the McCall indoor hatchery building, eggs are actually harvested and fertilized at the hatchery's South Fork Station.

Located 50 miles from the hatchery on the South Fork of the Salmon River, this is the only trapping facility supplying the McCall hatchery broodstocks.

Each season (June to September) approximately 500 female and 500 male summer chinook salmon are captured at the station. The fish are then hand-sorted by sex, and "flushed" in preparation for artificial spawning.

Eggs are collected first. Immediately after their release from a female, virtually all of the eggs are held and fertilized with the sperm, "milt", of a single male. The egg and milt mixture is held in water to allow for even fertilization. Once they are well into the "eye-up" stage, the eggs are counted, sorted and recorded. Finally, they are packed in hatchery incubation trays and transported to the McCall facility.

Upon arriving at the indoor hatchery building the egg trays are stacked together into large systems called "Heathstacks". The stacks are monitored, watered, disinfected and fed as units. The gravity-fed water system of the hatchery is used to deliver nutrients, and other needed chemicals.

A total of 352 incubation trays are fed by the water supply, which initially passes through an ultra-violet light system. This system purifies 260 gallons of water per minute, with no effect on its temperature or chemical composition. With all trays in use approximately 2.5 million fertilized eggs can be hatched.

Water flows through the Heathstacks for the 3 month growth cycle needed for the fertilized eggs to develop and hatch-out as sac-fry. With no predation pressures the sac-fry rapidly exhaust their yolk sacs, and develop to the "swim-up" fry stage. Click here for an explanation and pictures of the early stages of development.

At this point they are transferred into one of the 14 indoor nursery vats. Here they will feed and compete with other fry for the first time. These tanks are fed by the same water supply, at a rate of 1,680 gallons per minute per tank.

Fish are reared in the nursery tanks for 4-6 months, until the reach approximately 2" in length. At this stage they are transferred to the outdoor raceways.