During this season, juvenile coho from the prior Fall’s spawn continue to be fed. These fish will be released next Spring. This is a good time to visit the hatchery’s native plant garden and wetland. In the Summer, the hatchery usually keeps the 2-year old rainbow trout on display in the glassed-in adult holding pond, located around the corner from the fish ladder.
Around mid-April, yearling coho are released into Issaquah Creek. Juvenile chinook, which hatched in December and January, are released into the creek around late May or early June. Both species are released as “smolts,” which means they are preparing to migrate from fresh water to salt water.
The hatchery staff transports 2-year-old rainbow trout to Pine Lake and Beaver Lake around Halloween. The hatchery will also release rainbow trout into Lake Desire and Lake Shadow, both in Maple Valley.
The salmon eggs begin to hatch in December, although the exact date depends on the water temperature.
Hatchery staff and volunteers spend the days keeping the trays clean and picking out dead eggs. This all happens “behind the scenes” in the incubation room, although usually a sampling of eggs are on display in the aquarium room, which is in the center of the main building (directly behind the salmon sculpture).
From January through March, salmon fry are moved to outside rearing ponds and hatchery staff begins feeding them. The rainbow trout remain on display on the north side of the hatchery.
Although the hatchery is open year-round, Autumn is the most active time of year, when adult chinook and coho salmon return to the Issaquah Salmon Hatchery.
Chinook are the first to return, with the first salmon usually showing up in late August and the bulk of the return arriving by mid-September through mid-October.
Coho generally arrive by late September through late November. The hatchery also sees a few sockeye salmon, which usually arrive late September through October.
Hatchery staff and volunteers begin trapping adult salmon for brood stock in September and continue through November, collecting eggs and milt (sperm), fertilizing the eggs, and getting them settled in incubation trays.
You can see the spawning at the hatchery on many Tuesday mornings during the Fall. (This process involves striking salmon on the head and cutting open the bellies of females to retrieve eggs and is not recommended viewing for small children).
From the hatchery bridge, visitors can see the adult salmon digging their redds (nests) and spawning in Issaquah Creek. Visitors can also get an up-close, nose-to-nose view of the salmon from the hatchery’s glassed-in fish ladder.
The Issaquah hatchery also raises rainbow trout, which are usually on display in the Fall in ponds on the north side (Sunset Way side) of the hatchery.
Tours of the hatchery given by volunteer educators are available during the week for groups of 10 or more. Get more information or schedule a tour.
