Vail Resorts Inc. said Monday it agreed to acquire Canadian ski-resort operator Whistler Blackcomb Holdings Inc. for roughly C$1.4 billion ($1.06 billion), further diversifying its resort locations as it seeks to make its season pass programs more expansive.

Vail Resorts stock, up 40% in the past 12 months, rose 6.3% to $153.06 in morning trading in New York.

The...