As crowds of visitors stroll along wooden walkways in Yellowstone National Park's Midway Geyser Basin, steam clouds billow from the colorful Grand Prismatic Spring. The best vantage point I found was a nearby hilltop after a short hike down a 1-mile dirt trail and a scramble up and over fallen trees and rocks. It gave a better look at the shades of blue in the spring and surrounding mineral deposits. I used a 400mm lens to reach across the pool and compress the image.
In honor of this year's National Park Service centennial, the Travel section is posting 100 park travel ideas and tips based on trips staff travel writer Christopher Reynolds has taken, along with photo-op advice from Times photographer Mark Boster. We'll post one per day through Dec. 31.
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See travel videos by Reynolds from around the world.