This journal from an internet hiking buddy, Rich Hale, who has done the rim to rim to rim four times before hanging up his internet site, adventurehiking.com, a few years ago:

The National Parks have some of the great trail hikes.  The key is to go when no one else is there, which means: not summer.  Watch the weather maps and spot a window of opportunity for a pleasant, un-crowded hike.  Winters in Zion National Park are often mild with 60 degree daytime temperatures possible.  DayHiker has hiked this majestic red canyon the past two winters around Jan 1, found the weather great and the accommodations (Desert Pearl Inn, Springdale) upscale.

Many first experience the Teton Range as a visual drive-by on their way to Yellowstone on Route 89.  Stop next time and experience first hand the geologically-recent, dramatically uplifted mountains with canyons sculpted by glaciers.  This is the European Alps, the Colorado Rockies, the California Sierra Nevada’s, the Himalayas in compact form … easily accessible and hikeable on well maintained, gently sloped switch back trails.

For a west coast hiker the quickest way to get a flavor of east coast hiking is to do all or part of the Presidential Traverse. New Hampshire, the “Granite State” with its motto, “Live Free or Die,” gives a hint about the trails. They are free from the structure of easy sloping switchbacks trails so familiar around Europe and the western U.S. The hikes are characterized by constant ups and downs and the pace is slow. The deciduous trees of the lower slopes often blanket a rugged trail of granite-lined ravines.

This hike is different, extreme as a day hike, and one of the best of the Hawaiian Islands.  The island of Kauai is known for its heavy rainfall, panoramic views, tropical forest and rugged coastline.  This 11-mile Kalalau Trail (one-way) follows the Na Pali Coast with its incredible views of five lush valleys, waterfalls, and ancient Hawaiian ruins.

This is one of the best day hikes in the world, and a must do for the serious marathon day tripper.  One optimal time for this Grand Canyon Rim to Rim hike is as late as possible in the season but while the North Rim Lodge is still open, which around October 15, the day I did it.

It’s not often one can do an extreme day hike by going down to a river and back up the same day. The Bright Angel Trail at the South Rim of the Grand Canyon affords that opportunity and has incredible views. A word of caution: Do this in the wintertime during good weather and be in shape. This hike is famous for people getting in trouble during hot weather along with their tendency to underestimate the uphill climb.

The day hiking wonderland of the Colorado Rocky Mountains has  54 peaks which rise above 14,000 feet. Long’s Peak is one of the more famous and rigorous “Fourteeners” and a “must do” for the extreme day hiker.

However, like the other hikes described on this site, be prepared mentally and physically for this day trek of 16 miles round trip and 4850 feet of elevation climb.

The Maroon Bells, which lie in the Elk mountain range in a canyon just beyond Aspen, Colorado, are probably the most photographed “Fourteeners” of the Rocky Mountains.  The incredible views up the valleys and through the passes make this a great day hiking experience. 

This Cactus to Clouds hike, to San Jacinto Peak at almost 11,000 feet in elevation, affords an interesting challenge for the extreme day hiker, going from the Palm Springs desert floor to one of the tallest mountain peaks in southern California! 

This unique hike to the top of Yosemite’s most distinctive visual feature, Half Dome, is rewarded with a spectacular view of the Yosemite valley below.  Hiking the trail one encounters the mist and grandeur of two waterfalls.

Having turned 70 this year, I was curious if I could do the Mt Whitney day hike again. Along with shorter hikes, the only “training” has been running.

I just re-read my article of last year’s Mt Whitney day hike on July 10, 2014… “I will wait until age 80 to try Whitney again so I can forget how tortuously boring and long the descent is.”

This is a killer hike! – A must for the extreme day hiker. With some careful planning, some conditioning, and the right mental attitude this can be a successful day and an unforgettable experience. Mt. Whitney is a 22 miles round trip hike, has an elevation climb of over 6000 feet, and is one of the most famous extreme day hikes.

While the US does have an amazing set of mountain ranges Sierra Nevadas, the Rockies, the Appalachians, the European Alps are spectacular and must be experienced by the serious hiker or the beach lover who’s hooked to all inclusive holidays with OnTheBeach and wants to try something that will complement his/her exciting lifestyle. Its terrain and mountainous views are perfect for thrill seekers who want to spice up their summer or weekend getaway. An increasingly popular type of day hike is a walking tour in Europe.

The Great Smoky Mountains has an interesting hike, the Rainbow Trail-Mt. LeConte-Bullhead Trail loop, with a 15-mile continuous loop without backtracking, and has an elevation gain of around 4,000 ft.