Southeast of Trento, the Trevalli ski area has 100km of pistes.
The Trevalli ski area part of the Dolomiti Superski region which has over 1,200km of pistes spread over 12 valleys that served by 450 lifts. While a single skipass gives access to the Dolomiti Superski region, keep in mind that the 12 valley are not all interconnected and you may need bus transport between valleys. Also, the snowfall in this southernly ski region is known to vary greatly season to season. Keep in mind that there is limited off-piste snowboarding in the Dolomiti Superski region -- it is prohibited in most areas and guides are highly-recommended in the others.
Overall, Trevalli is the 29th most popular snowboard & freeride destination of all 40 snowboarding resorts in Italy.