As the country's second most popular park turns 100, Grand Canyon faces an unprecedented number of existential threats. Eight experts weigh in on the major changes it will undergo during the next century.

Bringing cutting-edge technology to the backcountry.

The latest and greatest outdoor-gear projects from Kickstarter, Indiegogo and other fund-me sites.

  A blistering pace in the men's race led to a course record for the 114th Boston Marathon. While no Americans cracked the top three, Ryan Hall and Meb Keflezighi finished fourth and fifth, respectively. Men's Elite Top Finishes1. Robert Kiprono Cheruiyot (KEN), 2:05:52 (CR) $150,000 + $25,000 CR bonus2. Tekeste…

Europe's lowlands are becoming the mecca of solar-powered bike paths. We especially like this take on Van Gogh’s most famous work.

Also has back surgery

Subaru’s new Viziv-7 concept previews a seven-seat crossover

FLEXIBLE FLIERGood for Packed TrailsLike to blaze along your local fire road or creek path? The extremely light and flexible Paragon is tailor-made for off-road tempo runs and speed work. A sleek tread and multiple forefoot grooves make for a supple feel on the flats, but the Paragon doesn’t have…

Help me sort out the confusing world of sports sunglasses! I've recently started biking to work every day, and I need a pair of prescription sunglasses that work for cycling and for casual wear. I'm thinking that sunglasses with interchangeable lenses (some for the trail, some for around town) are the way to go. Are there any cost-effective ways to do this for prescription wearers? And what's the deal with all these multi-colored lenses: what color lenses should I use for which conditions? Josh Boston, MA

Hamilton cuts bicep in surf accident