The snowiest city in the United States was right under our noses this whole time.

After Thursday’s foot of snow in Boulder, the city clinched its snowiest winter on record, with at least 145 inches of seasonal snowfall, through Thursday evening. In fact, Boulder’s seen more snow than any other major U.S. city, defined here as having a population of 50,000 or more people.

Boulder’s exceptionally snowy winter can be attributed to a combination of things, but at the heart of it: it’s been a season filled with lots of upslope snow events. The main driver for snow in eastern Colorado is an area of low pressure east of the state pumping in cold, moisture-rich winds against the Rockies. When that air meets the Rockies, it’s forced to rapidly ascend, condensing into heavy snow.

A high frequency of such storms has generally kept Colorado snowy throughout much of the winter. That’s why Denver, Colorado Springs and Fort Collins are all running above their seasonal snowfall averages, and in most cases, by sizable amounts.

But Boulder has more than doubled those other cities’ seasonal snow totals. While Boulder typically sees more snow than the other Front Range cities, the gap is much wider this year. That’s thanks to a lucky, or, if you’re not a fan of the snow, an unlucky east wind.

“Boulder will do better than Denver in almost any winter storm Mother Nature can throw at us,” explained Boulder-based meteorologist Ben Castellani of BoulderCAST. “This is because Boulder sits in the premier geographic location for snow, definitely the best of any Plains city across the Front Range.The sharp rise of the Flatirons is the first significant obstacle easterly winds encounter. This rise of 3000 feet straight up on the west end of Boulder is the largest of anywhere in the metro area. For storms like this past Easter Sunday, the conditions are just right to have localized upslope enhancement.”

Two big Boulder storms stood out in Castellani’s mind: A late November 23-inch snowstorm, and the 19.5″ Easter snowstorm. Denver only saw about 10 inches of combined snowfall from those two storms, while Boulder felt the brunt of the snow on both of those occasions.

“These storms were two different beasts, however,” Castellani said. “The former was characterized by a near-perfect upslope setup for Boulder around a strong surface low, while the latter had less-ideal upslope originating largely from an Arctic high, but which lasted much longer and had (lots of cold air).”

Enough of that snow rocketed Boulder’s seasonal snowfall up to 145 inches, with still potentially more to come. While that’s impressive, it’s often not enough to win the title of America’s snowiest city.

Usually, Great Lakes cities like Buffalo, Rochester, Albany or Syracuse, New York see more snow in an average winter than Boulder does. So would Erie, Pennsylvania or perhaps even Duluth, Minnesota or Grand Rapids, Muskegon or Kalamazoo, Michigan. But almost all of those cities had sub-par snow seasons (none of them saw more than 90 inches).

Along with the so-called lake effect snow belt, sometimes, the Interstate 95 corridor can get slammed by enough big snows to challenge such a mark, like Boston’s crazy 2014-15 winter.

But even there, forget about it. Boston’s only seen 15 inches of snow this winter and New York has only seen five paltry inches of snowfall. And Boulder’s 145-inch snow total is more than 480 times more than Philadelphia’s seasonal total (0.3 inches).

Other western cities like Rapid City, South Dakota (about 84 inches of snow), Casper, Wyoming (104 inches), Flagstaff, Arizona (70 inches) and Great Falls, Montana (100 inches) come reasonably close, but they’re all still a sizable ways off from Boulder’s impressive mark.

And yes, Boulder’s 145-inch total is way ahead of even Anchorage, Alaska (about 90 inches) and Fairbanks, Alaska (about 85 inches) and Juneau, Alaska (about 72 inches), though the latter two don’t meet the population threshold of a city with 50,000 or more people.

To be clear: there are other places in America that have seen more snow than Boulder, but none of them are as big as Boulder is, or frankly, even close. If you squint, you can find a lake-effect snow hub or two that’s had about as much or more snow than Boulder: take Marquette, Michigan (205 inches – population of about 20,000) for example. Or, a Canadian border-straddling town like Caribou, Maine (138 inches – population of about 7,600).

Of course, Colorado’s ski resorts have all seen substantially more snow than Boulder, as well. But as far as any sort of a city, it’s Boulder that’s king of this winter’s snow.