There are pros and cons to visiting any popular sites in the offseason, but here's an argument to visit two more:
■ Great Smoky Mountains National Park (Tennessee and North Carolina). More than 9.5 million people visit the park annually, which makes it the most popular in the U.S. parks system. The park comprises 800 square miles, 80 percent of which is covered, in three seasons, by the canopy of leaves from more than a hundred species of trees, including hickory, oak and maple.
In winter, that vegetative screen is removed. Don Barger, southeastern regional director for the National Park Conservation Association, said vistas from the more than 800 miles of hiking trails are "an entirely difference experience; it's almost like hiking out west."
In summer, thanks to humidity and the blue wisps of smoke that emerge after rainfall (hence, giving the park its name), visibility might be 25-30 miles. In winter, when fewer than 2,000 people visit, it's more like 100 miles.
Runoff from melting snow -- Great Smoky Mountains has 10 peaks that top 6,000 feet in elevation and averages 6 feet of snow on the peaks annually -- freezes, "making your mountainside waterfalls a festival of water and ice. It's just gorgeous," Mr. Barger said.
■ Ski resorts in summer can be thrilling. Although Whistler Blackcomb in British Columbia still has skiing until the end of this month, the lower elevations have been prepped for a wide range of adventures.
PEAK 2 PEAK is a 2.7-mile gondola ride between the Whistler and Blackcomb mountaintops. The gondola runs generally are closed for a few weeks of servicing right after ski season ends and going into autumn. Check www.whistlerblackcomb.com for dates.
Ticket prices vary and second-day free ride deals exist. Children can ride for as little as $22 USD, adults up to $49.
Want to see a bear? There are no guarantees, but more than 50 black bears live on the mountains, and tour options include 4-x-4 vehicle rides to Yogi and Boo Boo's neighborhood. Prices range from $164 USD to $173.
And what are tall trees without a zip line or two? Ziptrek Ecotours offers a network of suspension bridges, suspension stairways and zip lines. Size and age restrictions apply. Tours range from basic (two hours, $26.60 USD) to more elaborate (five hours and a meal, $210, www.ziptrek.com).