Fall Chinook Salmon Update (8/31/2023)

Idaho’s fall Chinook Salmon season opened on August 18, so I figured I better put out an update to let people know what is going on with this fishery. In this update, I will try to answer the questions people have been asking most frequently including what is the run looking like, what percent of the run is being trapping at Lower Granite Dam for broodstock, and what fishing regulations do anglers need to follow when they have both an Idaho and Washington fishing license and fish the boundary waters and/or both states during the same day. 

Run Status

Fall Chinook “officially” started passing over Lower Granite Dam on August 18, which means we don’t have a lot to go on to evaluate how this year’s return is progressing. However, I have provided the figure below that shows how the 2023 preseason forecast (bars furthest to right) compares to previous year’s returns. If this year’s forecast is accurate (they have been on the low side in recent years), we would see a similar return as the previous three years which provided fisheries that lasted through the entire season. The good counts at Bonneville Dam suggest that this preseason forecast may be on the low side once again.

When and Where to Fish

To help those of you who were wondering when the best time to fish for fall Chinook is, I have provided the figure below that shows the average run timing (for the past five years) for adult fall Chinook Salmon at Lower Granite Dam. Based on this information, the second week of September is when the fish counts at Lower Granite Dam typically peak, and once the counts peak, they typically stay up for two to three weeks. Based on the adult Chinook Salmon counts that have occurred at Bonneville Dam for the past five days (11,000 to 21,000), the fishing should once again get good around the second weekend of September. 

For those who like to fish in the flowing rivers such as the Clearwater upstream of the Potlatch mill, the Snake River upstream of Asotin, or the Salmon River, the farther upstream you want to fish, the later you will want to wait. One reason for this is that when many of the fish reach the confluence area, they hold there in the cold water of the Clearwater River. The reason for this is they are waiting for the Snake River to cool down before they begin their journey upriver. The Snake River typically cools down around mid to late September. As such, if you want to fish in the Snake River above Asotin, you won’t see a lot of fish until after mid to late September. For the Salmon River, you may want to wait until October. Fish will enter the Clearwater River earlier than the Snake because it has cold water, but fishing typically doesn’t get good until late September. When looking for places to fish it is important to know that when the fish first get to areas they want to spawn, they tend to hold in the deeper pools and runs, and then as they get closer to spawning, they will start moving into shallower water near gravels bars and pool tail-outs.

Trapping Broodstock at Lower Granite Dam

The fall Chinook Salmon hatchery program has played a key role in why fall Chinook Salmon returns to the Snake River basin have improved dramatically since the 1980’s and 1990’s. Three hatcheries rear and release fall Chinook Salmon in the Snake River basin. Their overall goal in the past has been to release 5.65 million smolts into the Snake River basin with about 80% of these fish being released upstream of Lower Granite Dam. The broodstock for this program is collected at a fish trap located on Lower Granite Dam’s fish ladder. These fish are trapped in a manner to help meet broodstock goals and reduce handling of wild steelhead. To meet these goals this year, broodstock started being collected on August 18 by trapping 70% of the fish passing up the fish ladder. For marked fish (fish that have a clipped adipose fin or some type of tag), they were kept for broodstock if their fork length was over 80 cm (about 33 inches total length) whereas if they were not marked (adipose intact and no tags detected), they were kept if they were over 70 cm (about 30 inches total length). Starting today (August 31), the trap rate dropped to 18% and the fish kept for broodstock will follow the same strategy as outlined above. What this means is that when we were trapping 70% of the run, about 65% of those fish counted at the window made it past Lower Granite Dam. Now that the trap rate is at 18%, over 90% of the fish counted at the window will make it past the dam and into the fishery.

Seasons and Limits

I’m not going to go into details on Idaho’s seasons and rules for fall Chinook because you can review them by clicking on this link (https://idfg.idaho.gov/fish/chinook/rules). However, I will provide these key points:

• The season in Idaho started on August 18, 2023 (The North Fork Clearwater opens September 1).
• The fishery will occur in the Snake River, lower Salmon River, and much of the Clearwater basin.
• The daily limit is three (3) adult fish (adipose clipped and unclipped fish can be kept).
• Fishing will be allowed seven days a week in all areas that are open.

For those who like to fish in Washington or with a Washington fishing license in the confluence area, you can view their regulations for the Snake River by clicking on this link (Washington Snake River Fall Chinook regulations). For the most part, Washington has the same limits and seasons as Idaho.

One popular area to fish for fall Chinook Salmon is around the confluence of the Snake and Clearwater rivers (see map below). Where it can get complicated is for those people who have both an Idaho and Washington fishing license (and permits) and fish in Washington only waters, boundary waters, and Idaho only waters. For those of you who like to do this, you should be aware of the following things.

When fishing the boundary water, you can only exercise the privileges of one license at the same time. For example, if you are fishing with two rods (Idaho allows this if you have a two-pole permit, Washington does not allow this) in the boundary water, you must tag your fish on an Idaho permit. You also must follow all other Idaho regulations such as in Idaho whoever hooks the fish must tag the fish (in Washington whoever lands the fish must tag the fish). In addition, if you fish the boundary water, you are entitled to have in possession only the limit allowed by one license regardless of the number of licenses in possession.

If you plan to fish in both boundary waters and Washington only waters, I urge you to call up the WDFW (WDFW Contact Info) to understand how they will enforce various scenarios. I copied the following wording from Washington’s regulations that anglers may not be aware of. “Before utilizing a Washington fishing license or fishing Washington only waters, any fish retained while using another state’s license must be returned to shore before continuing to angle.” In other words, don’t catch a fish in the boundary water and tag it on an Idaho permit and then continue into Washington only waters with that fish in your boat.

Get your rods ready, because the fishing is going to get good real soon!

Good luck!