Big Sky Country Snowpack Report - March, 2026
Hi, friends, and welcome to our third snowpack report of winter 25-26. Technically this will be the last report of the winter, as tomorrow is the first day of Spring. I’m sure you’ll be hearing from me again at least one more time, though. Facts are facts, and this winter has been an extraordinary one in terms of warm temperatures. Across most of the west, this has been the warmest winter ever recorded. Simultaneously, and perhaps thankfully, we have received average to well above average amounts of precipitation (more wet, than white) across most of the watersheds in our area and north in Montana, and we are wondering how that will shape our summer season.
Henry’s Fork Foundation hydrologist Dr. Rob Van Kirk addressed this fact in his daily report yesterday.
“Looking around the western U.S. as a whole, 2015 was the benchmark for low snowpack and early melt. However, 2015’s low snowpack occurred because of low precipitation all winter, whereas this year’s low snowpack resulted from warm temperatures, not low overall precipitation. …
So, while the late winter and early spring this year is looking very much like 2015, the two water years may still end up looking a little different in both water supply and ecological response because of the difference in how we got here.”
We built quite a bit of snowpack since the time of our last report a month ago which you’ll see when we dig deeper into the data, with an added boost coming last week in the form of the winter’s second “atmospheric river” event. That event brough piles of mountain snow and valley rain to watersheds primarily north and west of the Missouri Headwaters in Three Forks, while our local watersheds picked up at least a little moisture. Temperatures well above average and no meaningful precipitation are expected in the 10-day forecast. Typically, we continue to build snowpack for about another month, but that simply may not be the case this year. For now, we are left hoping for cooler temps and more snow through late March and April (not uncommon), and with some positive vibes noting that our area is, by far, the “Best in the West” when it comes to snowpack.
So, here we go, down the rabbit hole. Note that the plots and number numbers are based on NRCS Snotel data and online mapping tools, and the number are from March 18th, and that the plots did not auto generate % of Median and % of Median Peak SWE data for some reason, so we dug those up and added them to the text.
In the Madison watershed, Snow Water Equivalent (SWE) is at 84% of median for this date, down from 92% at the time of our last report. That puts us at 68% of our median peak snowpack with 32 days left in the typical snowpack building season. Comparing the Black line (this winter) to the greenish blue line (last winter) and the orange line (2024) you can see we are a bit below where we sat a year ago but significantly above 2 years ago. I added the 2015 data (light blue line below the black line) as a reference since Rob Van Kirk cited 2015 in the quote we included above.
In the Yellowstone River Headwaters, SWE is at 111% of median, which is down from 113% last report, but still really nice. Snowpack is currently 96% of the median peak value with 36 days remaining in the typical snowpack building time period. Compared to the last two years, this is AMAZING news. It’s good to be above the green, blue, and orange lines!
The Upper Henry’s Fork is a somewhat lower elevation watershed, and the snowpack is, as expected, lower. It’s been really warm down there, and Rob Van Kirk is predicting that the peak snowpack this year has already occurred, 28 days earlier than normal. SWE is at 65% of median, down from 82% at the time of our last report. SWE is 58% of the median peak with 25 days remaining in the typical snowpack building period. This puts us in a spot with less snowpack than last winter, and the year before. I added the 2015 data (light blue line below the black line)
So, there you have it, folks. Fingers crossed for cooler wetter conditions in coming weeks.
Until then, take care.
Matt and the BSA Crew
