The primary factors affecting late season (mid-March onwards) ski conditions are:

1. Altitude: The cooler temperatures at high altitude preserve a better snow surface. It is particularly critical that the snow set up at night. Overnight freezing allows for more grooming, often allows a corn surface to develop when the top layer softens, and prevents the snow from becoming progressively sloppier each warm day.
2. Exposure: North exposure becomes more and more important as daylight hours lengthen. The less direct sun exposure, the slower will be the transition to spring conditions. With north exposure, the steeper runs will get less direct sun and preserve the snow best. Don't forget that with south exposure, the situation is reversed: steeper runs will get more direct sun.

Within a group of ski areas, the one with the highest altitude and greatest proportion of steep north-facing terrain will nearly always have the best spring surface conditions. However, there are some secondary factors which also influence late season ski conditions.

3. Maximum snow depth: If snow preservation is good, the maximum base is usually attained in late March and very little coverage is lost by the typical mid-April closing dates of most destination resorts. A deep stockpile of snow is more critical for areas remaining open in May and later months. Other factors being equal, heavier Pacific type snow will build a higher base than the dry snow of the Rockies.
4. High spring snowfall to refresh the surface: Winter weather patterns usually prevail through the end of March, with snowfall at most areas steadily declining thereafter. However, in the Continental Divide region of Colorado, the April snowfall average of 50+ inches is comparable to the winter months. In Utah's Cottonwood canyons, the April average is lower than the winter months but still 60-70 inches.
5. Management maintenance of the ski area: How much terrain remains accessible with reduced lift operation? Is grooming maintained? Salting of the groomed runs is a big plus in warm weather to delay the onset of a slushy surface.
6. Proximity to population centers: A significant local population base is needed to make it economically viable to keep a ski area open through spring.

Analysis By Region:

The Pacific Northwest's best March/April skiing is found at the higher altitudes of Mt. Bachelor (9,000 ft.) and Whistler/Blackcomb’s alpine region (over 7,000 ft. and farther north). While most other areas in the region will have deep snow bases, the surface conditions at low elevation will be slushy if it hasn't snowed recently. In May/June Mt. Bachelor still offers 3,000 total vertical of Summit corn plus lower mountain salted and groomed runs. Summer skiing, on groomed and salted permanent snowfields, is available at Timberline (1,500 vertical) and Blackcomb (800 vertical).

In California, Mammoth (top 11,000 ft.) is the standout area, running through Memorial Day in 90% of seasons and to July 4^th about 1/3 of the time. Mammoth is also the only area outside the Northwest to salt its groomed runs. At Tahoe, Kirkwood's steep runs up to 9,800 ft. are the best bet until it closes in early May. Then Alpine Meadows (top 8,700 ft.) will operate into late May or June depending upon snowpack.

In Northern and Central Colorado, all of the Summit County areas operate to early May due to altitude (top 12,000 ft.) and proximity to Denver. A-Basin is the best ski area in North America by criteria 1,2 and 4 above, and thus operates through May in low snow years and well into July in good years. Copper Mt. (also predominantly north exposed) is next best in this region, followed by Winter Park. Vail and Breckenridge are more erratic due to substantial amounts of terrain with sunny exposures. Steamboat, despite its high snowfall, has the lowest altitude and worst exposure in the region.

Nearly all of the Southern and Western Colorado areas are ideally suited for late season skiing for both altitude (up to 12,000 ft.) and north exposures. Aspen/Snowmass, Crested Butte, Telluride plus Taos in New Mexico all have steep terrain which can retain a packed powder surface well into April. Due to remote location, these areas often close in mid-April with their deepest snow depths of the season.

In Utah, the best late season spot is Snowbird from both altitude (top 11,000 ft.) and terrain perspectives. It is also the only area open in May. Alta and Brighton top out 500 feet lower than Snowbird and have more variable exposures. Solitude and Park City’s Jupiter Bowl extend up to 10,000 ft. Utah is the warmest of the continental ski regions of North America, so spring conditions are common below 9,000 ft. from mid-March onwards.

Few of the Northern Rockies areas have good exposures, and spring surface conditions on ungroomed terrain like much of Jackson Hole can be very difficult. In the U.S. Big Sky has the highest altitude (top 11,000 ft.) and coolest temperatures. Most of the Kootenay areas near the U. S. / Canada border are relatively low in altitude (nothing over 7,000 ft.) and spring conditions are likely. The Okanagan areas are farther north and a bit higher and cooler than the Kootenays. The Alberta Rockies, despite low snowfall, are the best bet for late season for both higher altitude and coolest temperatures. Sunshine (9,000 ft.) and Lake Louise (8,500) are also the only areas in the region open later than mid-April, although late season coverage can be an issue in below average snow years.

Late season snow conditions in the Northeast are usually difficult. Good spring surface conditions are dependent upon consistent freezing of the snowpack most nights and low humidity. The East usually fails on both counts due to low altitude (nothing lift serviced over 4,200 ft.) and with increasing rain frequency in the spring months the surface often resembles a granular snow cone. It would be quite rare for eastern conditions in April and May to be comparable to the western areas we have recommended. It is not surprising that in spring many eastern skiers climb Tuckerman's Ravine for its steep runs starting above 5,500 ft.