It's like winning the lottery—literally. While anyone can drop $5,000 to sign up for a commercial raft trip down these 277 miles of the legendary Colorado River, running your own requires a Park Service permit awarded in an annual lottery ($25 to enter, $100 per person for up to 16 people if you draw; nps.gov/grca). Odds are it'll take five years for your number to come up, which means you have time to prepare. You'll want to develop good oar-boat technique (consider a class with OARS; oars.com) and run some practice expeditions on big Class III rivers like Utah's Cataract Canyon and Idaho's Hells Canyon. When it's your turn on the Grand, make sure you have at least one ringer in your group, such as a former professional guide, and use a provisioner like Professional River Outfitters (proriver.com) to supply boats and pack them full of food. Then it's 25 days of utter glory.