How vast is your national park knowledge? Each month the Traveler offers you a chance to prove your mettle with Mystery Spots and Mystery Photos. To further encourage your participation, we're going to start handing out prizes.

Don't worry, these prizes won't be large enough that you'll have to declare your winnings on your tax return. Rather, they'll be fun, useful items that can add to your national park memorabilia.

Here's how you can qualify: Each month, we'll take the names/cyberhandles of the readers who correctly answered Mystery Spot or Mystery Photo puzzles, place them in a hat, and pull out a winner. That winner will receive one of Ranger Doug's retro national park windshield stickers.

Come the end of the year, we'll tally up the winners and hand out something else -- perhaps a park guidebook, maybe a commemorative park hat or coffee cup -- to the individual with the most monthly wins.

Of course, to be considered a winner, we'll need your name and address, so when you see your name posted as the monthly winner, email us at [email protected]