First run in 1983, the LT100 sends runners climbing and descending 15,600 feet (that’s 2.95 miles up and down!), with elevations ranging between 9,200 and 12,620 feet. (Take a moment to catch your breath before reading on.) The course is 50 miles out-and-back, starting at 10,200 feet. The centerpiece of the course is the climb up to Hope Pass at 12,620 feet – which runners encounter on both the outbound and return legs.
In most years, fewer than half the starters complete the race within the 30-hour time limit. [Thanks to Wikipedia for the background info.]