You find the location and then map the route. Click the start and then at the finish, and it'll usually autmoatically draw the route for you. Turn on elevation, and the data is there. It might not be exact, but it'll be close enough for government work.

You can do something similar on google maps and/or goodle earth, too, IIRC.

Or, just tell us the exact start location (city and road name) and where the summit is, and someone else can do it.