The robust return has a welcome sign to ecologists, who have been working to bring the threatened kokanee salmon run back from the brink.
"For the first time in over a decade there are several hundred kokanee salmon spawning upstream," says ecologist Hans Berge.
Berge and others have been working to increase their numbers and improve their native spawning areas in the creeks that run into Lake Sammamish.
For decades an old-fashioned culvert on Ebright Creek blocked the salmons' natural path.
"So they would swim upstream a half a mile, and they would be stopped," says Berge.
But now the culvert is gone.
"Now that that 18-inch culvert has been replaced with this larger box culvert," says Berge. "Fish are able to go all the way upstream, well into a pristine canyon environment where they used to spawn naturally."
Ecologists say parts of the creek the kokanee can now reach is about as good as it gets for fish.
"It's just fantastic habitat, it really is - great tree canopy, so there is a lot of shade for the water to keep it cool," says Berge.
Also helping this year's record run are efforts made over the past several years to make sure more young fish survive to return again.
"It's a wonderful opportunity for fish to come back and see this habitat that they haven't been in in many many years," says Berge.
State and King County ecologists have been working to boost salmon runs in the Sammamish watershed for more than a decade.