I knew that Whistler-Blackcomb, in BC, was a big ski resort; but only recently did I get how big. While doing an overview of family ski resorts. I looked at the "vertical drop" for many mountains. (That's the top-to-bottom measure, from the highest point where you can ski, down to the base.)

•  in New England, a vertical drop of 2800' is looking good
• in New York State, Lake Placid has the highest vert in the east, at 3450'. Catskills ski slopes shrink down to about 1400.
• in PA, Blue Mountain has the biggest vert in the Poconos, with, um, 1082'.
• Colorado -- hey, its the Rockies! Vertical drops of over 3000 feet are common; Snowmass has 4400 vertical feet.
• Utah has the Rockies too, i.e. the Wasatch Range.  Snowbird, for ex., has 3240 feet vert.

But get ready for Whistler-Blackcomb (which isn't even in the Rockies):  Blackcomb has the highest vert in North America, at 5133 feet, usually called "one mile"; Whistler's a smidge lower, at 5018 feet.

No wonder Mom gets tired doing a couple of runs. 

Read more about Whistler- Blackcomb:  site of the 2010 Olympics; 1-1/2 drive from Vancouver BC, along the scenic Sea-to-Sky highway; and often ranked as one of the world's top ski resorts.  Whistler's skiable area is giant, too: 8,171 acres.

And by the way...

You may be wondering, if vertiginous Whistler and Blackcomb mountains aren't in the Rockies, then what mountain range are they in? The answer is BC's Coast Mountain Range, even though these mountains are not on the coast.

Another feature about Whistler-Blackcomb is low base-level elevation: Whistler village is only about 2100 feet above sea level, unusual for a mountain resort. Nice side effect: no problems with high altitude. (Some Colorado ski resorts, for instance, have elevations of 7500 or even 9700 feet; Utah ski resorts, too, can be lofty, sometimes causing visitors to have temporary high-altitude symptoms, such as headaches.)