Top photo%3A A %26quot%3Bbison jam%26quot%3B in Yellowstone%27s Hayden Valley%E2%80%94traffic gridlock caused by tourists moving through a bison herd%E2%80%94is a common occurrence in summer. Image courtesy Jacob W. Frank%252FNPS. Middle photo%3A%3A Summer crowds move along the boardwalks encircling Old Faithful Geyser and other features in the Upper Geyser Basin. Image courtesy Neal Herbert%252FNPS. Immediately above here%3A Visitors from around the world wait for Old Faithful to erupt. Image courtesy Jim Peaco%252FNPS
Top photo%3A A %26quot%3Bbison jam%26quot%3B in Yellowstone%27s Hayden Valley%E2%80%94traffic gridlock caused by tourists moving through a bison herd%E2%80%94is a common occurrence in summer. Image courtesy Jacob W. Frank%252FNPS. Middle photo%3A%3A Summer crowds move along the boardwalks encircling Old Faithful Geyser and other features in the Upper Geyser Basin. Image courtesy Neal Herbert%252FNPS. Immediately above here%3A Visitors from around the world wait for Old Faithful to erupt. Image courtesy Jim Peaco%252FNPS