Chinook fishing is both fickle and predictable. Hatchery managers and fisheries managers can tell you when the fish are going to arrive. They have lots of history to guide them.
But for anglers, river conditions, run size and fishing pressure affect your chances of landing a few of these prized fish.
Well, the chinook are arriving, and as we've known for months, it's a smaller run than in recent years.
Here are some numbers to mull over. Anglers caught more than 500 adult chinook in the Main Salmon and about 40 in the Little Salmon in about four days during the extended Memorial Day period. Roughly 2,000 adults are expected to be available for sport harvest in those rivers. That means about a quarter has been landed so far.
But here's the catch. That 2,000 fish is an estimate that has to be confirmed by the actual number of fish that cross Lower Granite, so it could be less.
Simple math says 25 percent of the fish have been caught so far, but beware that math doesn't apply to the calendar.
Ed Schriever, fisheries bureau chief for Idaho Fish and Game, said the chinook are quickly moving upstream, and they're in great condition. When the peak of the run arrives, which is traditionally in June, the harvest quota could go really fast.
"We will be watching it very closely in the coming days with hopes that no closures will need to be instituted through this coming weekend," he said. "However, closures are likely in the near future."
So there's your alarm bell. Get to the Riggins/Whitebird areas now. If you're early, you can always come back later. But as Schriever warned, "don't wait until it's over."