There are many incredible drives in the National Park System, but two of the best, at least in the western half of the country, are Trail Ridge Road in Rocky Mountain National Park and Going-to-the-Sun Road in Glacier National Park.
Both feature sweeping views of their respective parks, both have sections that can deliver moments of vertigo, both come with wildlife -- primarily elk in Rocky Mountain and mountain goats in Glacier -- and both are engineering marvels.
Both roads run about 50 miles -- Trail Ridge Road traverses 48 miles between Estes Park, Colorado, and Grand Lake, Colorado, while the Sun Road runs 50 miles between St. Mary, Montana, and West Glacier, Montana. It took nine years, from 1929 until 1938, to complete Trail Ridge Road, while construction of the Sun Road began in 1921 and was finished in 1933.
Both roads are slow to open in spring/summer as crews need weeks and weeks to remove winter's snows. And both close somewhat early in fall as winter reappears.
Which is your favorite, and why?