Runoff Update and Season Fishing Forecast – by Walter

I’m going to keep this update brief since I posted the likely fishing dates and something of an outlook for each body of water a week ago on our general fishing report.

We had an exceptionally snowy winter, with snowpack topping out at 175% of normal for the date in mid-late April. Since then, it has generally been warm and wet. Runoff started ten days early on the Yellowstone, with the river going out of shape around April 26, and snowpack as a percentage of average for the date has nosedived, to 125-odd percent of normal.

What does this mean? We are going to have somewhat high streamflows and somewhat late starts to the season on many popular fisheries this season, but the dates they drop out of the spring melt will only be perhaps a week after the “normal” date. Note that since 2001 we have had six years with above normal snowpack and streamflow and late ends to the melt, about three years with “normal” snow, streamflow, and fishable dates, and every other year has had some combination of low snowpack, streamflow, and early fishing dates. So the perception many people have of “normal” has been skewed.

Some details:

The Yellowstone River (except the stretch below Yellowstone Lake that opens July 15) will drop out of runoff around July 5-10 and have a probably-excellent Salmonfly hatch beginning at the same time between Gardiner and Livingston and marching upstream into the park in the middle ten days of July. Flows should be good and cold all summer after that.

The Lamar Drainage (Slough, Soda Butte, and Lamar) will drop into shape between July 5 and July 15 depending on the section in question, with the best fishing early in the rough water and on lower Slough Creek and the meadow sections of Soda Butte getting good around mid-month. These too should be nice and cold through the summer, though there will be significant changes to Soda Butte and probably the Lamar due to the high water, with many old channels gone and the new ones not yet established enough to fish “right.”

The Lower Gardner is already fishable on a day-to-day basis, with fishability/clarity depending on a couple cold nights, but it will get much better after June 15 and especially June 25. The upper Gardner and tributaries will be too high and cold even if clear enough until at least June 20, with most getting fishable around July 10.

Meadow-Type Small Streams in Yellowstone that drain the park’s central plateau will be marginally fishable by June 15 and good by July 1. Rough and tumble small streams both inside and outside the park will generally be too high until at least July 15.

The Madison Drainage in YNP (Madison, Firehole, and Gibbon) have all dropped into fishable shape, though the Gibbon’s meadows are still too high. All of these waters have fished surprisingly well for the first week of the park season. The Firehole will get questionable after lunch due to warm water temps by June 20 and will be too warm below Old Faithful to be worth fishing at all by July 4. The Gibbon and Madison will fish fine all day through June and should fish SOME until mid-July.

This is probably the last update of this kind this year. Instead check out the general fishing report from here forward.

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