Hm. I actually think that a destination waterpark geared toward kayakers would be neat. Get on the lift with your kayak, ride up, jump in, drop some absolutely sick manmade rapids on the way down. (can you imagine a series of 12' - 20' boofs all in a row, perfectly designed to be safe and fun?)
Flipping on my engineering mind.... (sound of fans spinning up)
In round numbers:
Water flow rate = 15mph = 22 ft/s
Depth = 4 feet
Channel width = 15 feet
That means the areas is 60 ft^2, and the volumetric flow is about 1320 ft^3/sec, or about 10,000 gal/sec. This is about 600,000 gallons per minute.
To lift that much water 3450 feet top to bottom of Vail requires 4.54 million foot-pounds of work every second.
This is about 8160 horsepower. The pressure head will be about 1470 psi at the bottom. No high-volume pump can provide a pressure that high, so we'll have to use stages.
An average utility pump can turn about 60 psi. So we'll need 26 stages, at 310 HP each, for a total of 6 megawatts of power, enough for 1500 homes. At current utility rates, that will be about $550 an hour or $4400 a day just for the electricity
Assuming a 30 degree slope, the project will also require 6000 feet of 2' diameter steel pipe, and about 6000 cubic yards of concrete - about 60 cement trucks worth.
That's one hell of an engineering project, but certainly not impossible.