Mention Yellowstone or Rocky Mountain national parks, and Americans can quickly conjure images of Old Faithful or Longs Peak. Likewise, Californians can easily picture the desert cactus of Joshua Tree and Half Dome in Yosemite.

But mention secluded Kobuk Valley in Alaska or the remote Channel Islands off the Southern California coast and the mental image may not come as quickly. These 20 least-visited of the 58 national parks in the U.S. offer the same types of natural beauty, exotic wildlife and adventurous outdoor activity as their more popular counter-parks do -- but with smaller crowds and enough adventure to satisfy even the most daring.

-- Kelsey Ramos, Los Angeles Times