While Big Sky may be a bit more challenging for skiers who like to ski in the backcountry, it can be a great place for those who like to ski on groomed terrain.
Big Sky's grooming crew does a great job of maintaining the slopes, and the variety of terrain makes it an excellent place to ski in March. Additionally, with a wide range of terrain, Big Sky is a great place for skiers of all abilities to enjoy spring skiing.
The cold days that can still strike Montana in March are greatly blunted by the superior lift system at Big Sky, which includes a number of heated and bubbled lifts. Big Sky has more advanced chairlifts than any other ski resort in North America.
The northerly-facing terrain at Big Sky can hold chalky cold snow well into the spring due to the resort's northerly latitude and its relatively high elevation for Montana.
Those looking for corn snow and more sun exposure in March at Big Sky can look to the Liberty Bowl, which is known for its wide-open terrain and sunny exposure. This area receives a lot of south-facing exposure, making it a great spot for skiers looking to enjoy some spring sunshine.
Additionally, the Moonlight Basin area of Big Sky is known for its sunny exposure and is a great spot for skiers looking to enjoy some spring corn snow.
What matters when it comes to snow for March skiing:
Ski areas with higher elevations and more northerly latitudes can keep snow colder when thawing temperatures in March or during warming events degrade other resorts' snowpacks. Aspects have the same affect, so the snow at a ski resort with more east or south-facing slopes will suffer more quickly as the sun grows stronger into March and the later spring.
For that reason, ski resorts with more north-facing terrain will be able to shelter snow more thoroughly into and through March. The most important factors for good snow preservation in spring tend to be elevation and north aspects, so the ski resorts with the highest elevations and the highest percentage of north-facing slopes tend to be those that preserve their snow best. More explanation on this topic can be found on our snow rankings page.
Lots of east and south exposures coupled with cold temperatures at night can put ski slopes into a nasty freeze-thaw process, wherein the ski resort becomes an ice rink overnight and doesn't revert to being skiable until the sun thaws things out. If the sun doesn't come out, however, skiers can be stuck with terrible conditions for days on end.
So, quite simply, in March, look for resorts with high elevations and high percentages of north-facing terrain (~50%+).