It’s a busy time of year at the Ballard Locks Fish Ladder — hundreds of sockeye salmon are heading upstream for the annual migration.

In the past week alone, over 3,500 sockeye have passed through the fish ladder, according to the Washington Department of Fish and Wildlife daily counts.

The salmon have been counted every year since 1972, starting on June 12th each year and counting through July. The results are used by Fish and Wildlife and the Muckleshoot Tribe to determine if there are sufficient sockeye to open fishing seasons.

Starting now, state and tribal managers make weekly projections of the expected total run size based on the current counts. And, when and if they expect the total run size includes sufficient surplus fish above the escapement goal of 350,000 sockeye, sport and tribal fishing seasons will open.

They’ve counted a total of 4,687 sockeye passed through the Locks so far this summer (between June 12-30).

U.S. Army Corps of Engineers Public Affairs Officer William Dowell says July 4th is typically the height of the run, but it seems last week they were at their peak, with 1,293 passing on June 26th.

The Fish Ladder is free and open daily from 7am to 9pm, with guided tours available for groups and individuals.