Madison River Ice Gorge



It’s all downhill from here folks. Although December 21st marked the beginning of winter with the Solstice, today officially marks the middle of winter. So, we thought this would be a good time to provide you with some interesting notes about how our January winter conditions compare to long term averages (thanks to our good friend Tom DiMeola), and the phenomenon that occurs on the Madison, locally known as “the gorge.”


It was a bitter cold start to 2017 here in Ennis. We had the coldest mean low (7 degrees Fahrenheit), the lowest mean high (27 degrees Fahrenheit), as well as the lowest mean average (17 degrees) in 15 years! In town, Tom observed 10 days below zero (the most prior to 2017 was 7 in 2008), the highest January snowfall (9 inches) in 15 years, 14 days with wind gusts exceeding 30 mph (tied for the most in 15 years), and an overall high of 41 degrees (the lowest January high he’s ever recorded). But dig out those Hi-Vis Griffith’s Gnats and 5x tippet; the forecast is calling for low 40’s this weekend!

That definitely explains this year’s substantial ice gorge on the Madison River. If you’re not 

familiar with what locals refer to as “the gorge,” you probably won’t recognize the Madison in Ennis right now.


Here’s what happens: As both air and ground temperatures plummet well below zero, small ice discs known as frazil ice begin to form in the water and attach themselves to the bottom and to each other. As this phenomenon continues the ice discs build up rapidly. If temperatures remain cold enough for long periods of time, the result is pretty spectacular. Ice builds and eventually overflows riverbanks and spreads out into the valley bottom, sometimes over a mile wide near the lake as viewed from Norris Hill. In especially frigid winters, the gorge has extended up river beyond  Varney Bridge. Though that hasn’t quite happened yet this winter, the gorge did make it above 8 Mile Ford. That’s approximately 12-13 river miles of ice! In town, the river gorged enough so that water and ice began flowing over the highway at the entrance to the town launch (which is now under tons of ice) and nearly touching the bottom of the town bridge!

In the last week or so temps have warmed slightly and we’ve started to see signs of life from the river in town. Flowing water constricted to small channels has begun to appear after an unusually cool January.


No one is really sure exactly how fish respond to these conditions, but there are few theories. Some fish make runs upriver to more open water, while some fish move downstream into Ennis Lake for the deep winter months. And some fish surely die  in shallow sections where ice displaces flowing water. But water is still flowing under that ice somewhere, and fish probably seek out deeper spring fed water refugia until the ice  break up. The main channel can open back up almost as quickly as it can form as soon as high temperatures rise into the 30’s and 40’s. The remnant ice on the banks and in the floodplain can hang around for considerably longer, sometimes well into late April.


The gorge has important effects on the river, especially in the Varney to Lake section. Those of you who love fishing the “Channels” section at Valley Garden have the ice gorge to thank for myriad of braids you can get lost in all day during August, ripping lips with fat chubbies. The ice has tremendous power, creating log and debris jams, forming new “buckets” (deep holes carved in gravel bottom), and even creating new channels themselves.


Think of it as a renewal of fish habitat every winter. Avid Madison River anglers and guides notice even subtler changes each year in the river substrate, which are important to learn for navigating drift boats and putting clients on fish. Channels taken in boats in previous years may be shallower or sometimes impassible the next year and vice versa, forcing guides to “re-learn” the river in certain sections. Hopefully all this ice and cold translates to a good snowpack, a slow melt, good late summer flows, and fat happy fish!


We're hoping to bring you more unique perspectives of life here in Trout Town, USA this year. One way in which we hope to accomplish this is via drones! For those of you not in Montana, we'll give you a better idea and perspective of the Madison River ice gorge. Check out our YouTube video below featuring drone footage of the gorge here in Ennis, by one of our long time guides, Mike Lum. The footage takes you from the front steps of the shop, out over the town boat launch, across the Hwy 287 bridge and back to town.