Avenue of the Giants
Humboldt Redwoods State Park, California
Many endurance races boast grueling treks through sun-scorched deserts, or chaotic routes through major U.S. cities. By comparison, the Avenue of the Giants, held in a magnificent evergreen forest 300 miles north of San Francisco, seems downright chill. To accommodate participants' different skill levels, organizers offer three races: a marathon, a half marathon, and a 10K. The paved route cuts through old redwoods, following a natural creek and the Eel River. And the scenic, near-sea-level race is a qualifier for the Boston Marathon (the event originated when local runners improvised a marathon tough enough to give them a shot at the 1972 Olympic Trials). Expect comfortable weather that will have you starting out with trademark cool and misty weather before the cloud cover burns away around noon.
New York City Marathon
New York, New York
The New York City Marathon—the world's largest 26.2-miler—needs little introduction. The race, a Big Apple fixture for more than four decades, hosts 50,000 participants from around the world and goes through all five of the metropolis's boroughs. Once you bring in the 12,000 volunteers and 2 million spectators in attendance each year, you've got a leviathan of a race on your hands. But, despite all the vastness, there's a neighborhood feeling too. Says Lauren Flinn, an organizer: "Marathon day is New York's biggest block party, uniting communities and celebrating the human spirit."
Hopkinton to Boston, Massachusetts
Third Monday in April (Patriots' Day)
Founded in 1897, Boston is the world's best-known and oldest annual marathon. It's also one of the most exclusive (runners must meet rigorous qualifying times to be eligible), as well as one of the fastest (in 2011, Kenya's Geoffrey Mutai ran a 2:03:02 on the net-downhill course—the speediest marathon run to date). Runners are bussed to Hopkinton for the race's start, passing through eight towns before finishing at Copley Square in central Boston. Highlights of the route include Wellesley College, where hordes of screaming coeds offer kisses to runners, and Heartbreak Hill, the 0.4-mile climb near mile 20 where many runners hit the wall. "Every serious marathoner should do Boston to experience the near-million spectators; the cheering, multigenerational families; the kids handing runners water and orange slices," says Neil Weygandt, who did 41 consecutive Bostons. "The whole city really appreciates the runners."
Heart of America Marathon
Begun in 1960, HOA is the fourth-oldest marathon in the country. It's also among the hardest—partly because of its hills, and partly because it's held on Labor Day in central Missouri, when the average temperature is 75 degrees and the humidity oppressive. But HOA, which usually attracts about 200 runners to its 6 a.m. start, is a classic. "People who come back to run year after year stress that they like its simplicity," says race director Joe Duncan. "It's a small-town, down-home tradition—and a relief from big-city commercial marathons."
Bonus: The post-race party and awards ceremony is held at Shakespeare's Pizza, named best college hangout by Good Morning America.
Pikes Peak Marathon
Manitou Springs, Colorado
The tagline for the Pikes Peak Marathon is "America's Ultimate Challenge." Don't say we didn't warn you. But if 6,000 feet of vertical gain over ten miles and 2,000 more feet of vertical gain over the next three sound like a blast, the Pikes Peak Marathon is your race (keep in mind you have to come back down). The associated Pikes Peak Ascent (just one way) covers 13.32 miles and 7,815 feet of vertical gain. "To have finished the race—with whatever motives going in—will end up being among a runner's greatest accomplishments," asserts director Ron Ilgen, adding that finishers "are extremely goal-oriented, focused, committed, and, yes, maybe a little crazy."
Valles Caldera Runs
Los Alamos, New Mexico
"The race happens on one of only six supervolcanoes in the entire world," says former director Rob Dixon. But that doesn't mean you'll be running across lava flows: the Valles Caldera National Preserve's 89,000 acres include several grassy meadows surrounded by mountains. Because it's crisscrossed by the San Antonio Creek, the East Fork of the Jemez River, and more than 3,000 grazing elk, you'll likely forget you're in the high desert of New Mexico. The Valles Caldera Runs (a 10K; half and full marathons) are held primarily on old logging roads, making for slightly less technical terrain. Even so, marathoners must conquer more than 2,100 feet of elevation change, starting at about 8,000 feet.