Low Water, High Water Temps: Major Impacts to Area Fisheries Beginning

If you’ve been following the news, you know that the NW United States has been under a nasty heat wave. We’re right in the bullseye even though we don’t make the news as often. Coming on the heels of a low snowpack year and an exceptionally hot and dry June, we’re starting to run into severe water temperature and flow problems that are hurting both fishing opportunities and area fish and fisheries. The governor has declared a state drought emergency. The long-range outlooks for summer 2021 do not provide much hope conditions will improve. Indeed, we’re now looking at our worst water year since 2007 or 1988.

Here’s a rundown of where we’re at and where we’re going. The hyperlinks will take you to relevant information pages.

As We Stand Now – A Summary

Water levels are drastically below normal. While the precise percentage varies from stream to stream, in general most rivers and streams are flowing at 30-40% of their historic averages for the date. For reference, these levels are closer to those commonly seen in early August than early July. Coupled with temperatures generally in the 90s at low elevation and the 80s even at 7000 feet in Yellowstone Park with bright sun, water temperatures are climbing well above normal. They’re already at levels seldom seen except during early August heat waves during previous drought years. The current water temperatures are unprecedented this early in the season.

Due to the high water temps and low water, some closures are already in place on low-elevation streams including the Jefferson, Shields, Smith, Ruby, lower Gallatin and East Gallatin, but near-universal closures on all larger rivers in Montana are likely soon. Except a couple marginal fisheries like the Shields, current closures are 2:00 to midnight “hoot owl” closures that allow for morning fishing. Without a break in the weather, full closures are likely on all major rivers except the Missouri, Bighorn, and perhaps the Madison upstream from Ennis Lake.

Yellowstone Park has not instituted any angling closures yet, though it should. Water temperatures in portions of the Firehole River have already reached 85 Degrees! This is undoubtedly lethal to the Firehole’s fish. We expect large-scale fish kills due to high temps have already occurred on this river.

Fire danger is high to very high and likely moving towards extreme levels. We are at stage II fire restrictions in Park County, Montana (as well as virtually all other counties in the area; no fireworks, kids), and the Custer-Gallatin National Forest, while stage one restrictions are present in Yellowstone Park.  We anticipate a very bad fire year in the region, possibly on par with 1988, or, for younger folk who don’t remember this, the recent apocalyptic fires in California.

Fire danger and water temperatures are increasing with no end in sight, while hope for increased streamflow is nonexistent before September rains.

Impacts on Fish and Fishing

High water temperatures and low flows are terrible for trout. Trout beginning experiencing thermal stress when water temps reach the high-60s. 73 degrees can be lethal. As such, Montana begins instituting 2:00 to midnight “hoot owl” closures when water temps hit 73 degrees three days in a row at any point during the day. 24-hour closures are instituted if temperatures fail to drop below 70 degrees during any 24-hour period. These closures remain in place until water temps remain below 70 degrees for three consecutive days and forecasts predict this will continue.

At any rate, fishing when water temps is over 68 is terrible, so it is best to leave the fish alone when temps reach this level.

When fishing when water temperatures may push into the danger zone, it is important to do the following:

• Avoid fishing during the warmest part of the day or in any condition when water is over 68-70 degrees.
• Play fish quickly to limit their exertions. Consider upsizing your tackle to enable bringing trout in quickly.
• Keep fish in the water – no hero shot photos.
• Use barbless hooks that are easy to remove.
• Fish high-elevation or tailwater areas that do not get as warm.
• Consider fishing for alternate species such as carp.

Given the duration of the low flows and high water temperatures, we anticipate severe negative effects on area trout populations. Large fish kills are likely in the Firehole, Gibbon, and Madison Rivers in YNP, which all receive hot geyser basin discharge. Limited trout kills are possible elsewhere. Large whitefish kills are possible in the Yellowstone River System due to a resurgence of Proliferative Kidney Disease, a parasite that thrives in the warm, low, weedy water we will have this year.

Impacts on YCFF Operations

Here’s the meat of the matter for many readers. Effects on our operations are beginning and will be severe for the remainder of the summer. These include:

• Drastically reduced fishing opportunities on large, famous waters including the Yellowstone River and many locations in Yellowstone Park. Even when closures are not in place, poor fishing or undue stress on fish will prompt us to refrain from fishing many areas until temperatures decrease and flows increase.
• Reduced fishing hours – We are already quitting by 3:00 and will shift this earlier if need be, even if we are not legally required to do so.
• Earlier starts – We will begin meeting for all full-day trips at 6:00AM this week, and all half-day trips will run in the morning.
• “Guide’s Choice” trips are required – Because options are limited, we expect all trips to have to run as “guide’s choice” trips in which we fish areas that are open and ethical to fish, regardless of client preferences. In general, the highest, steepest, and coldest water is what we will have to fish in order to operate at all.
• Likely full suspensions of our services – We anticipate having to shut down our guide services beginning sometime in mid-July and continuing until sometime in late August. Full closures through the 2021 season aren’t off the table. We will be getting in touch with clients booked in July and August over the next few days to discuss options.

Will YCFF Survive This Year?

Absent all the trout in area rivers dying from this heat and drought (which frankly is something we are beginning to worry about) or our house burning down due to wildfires (more likely, we are prepping “GO!” bags for this possibility), yes we will. We had a record June due to the July-like water levels and are selling off some of our capital (namely the jet boat Walter just bought) to see us through the winter, and Walter is lucky his wife Jani chose a steadier and more-lucrative career. We will get through this year more-or-less intact and hope for a strong resurgence in 2022.

That said, a second year in a row like this one will destroy rather than damage area fisheries and will mean Montana is no longer a world-class fly fishing destination, in which case I will most definitely be looking for something else to do…