Black and white photograph of a peak on the Cripple Creek Railroad in Colorado.

Black and white photograph of rocky landscape and train in motion on railroad tracks. Two engines and two passenger cars, all connected, are visible to the right of the photograph.

Black and white photograph of rocky landscape at Clyde. The front engine of a train is visible at the lower right edge of the photograph.

Black and white photograph of mines at Goldfield, Colorado. Taken by Robert Merrill from a stationary train.

Black and white photograph of a train crossing a curved trestle bridge.

Black and white photograph of rocks to the east of a summit. Railroad tracks can be seen through the rocky landscape.

Black and white photograph of plane landscape toward Colorado Springs, Colorado. Taken by Robert Merrill from a moving train.

Black and white photograph of the Mt. Manitou Scenic Railway in Colorado. A woman, possibly Lena Merrill, is visible at a distance. A sign to the right reads The Scenic Incline to Mt. Manitou Park.

Black and white photograph of Hanging Rock at the Pikes Peak Cog Railway.

Black and white photograph of the Pikes Peak summit from the timber line.

Black and white photograph of the Pikes Peak summit at a twenty-five percent grade above the timber line.

Black and white photograph showing a down-northwestard view from Pikes Peak Summit Plaque.

Black and white photograph of Lena Billington Merrill, seat on Pikes Peak.

Black and white photograph of Lena Billington Merrill aboard the Pikes Peak Cog Railway. Taken by Robert Merrill from the ground.

Black and white photograph of a tower on Pikes Peak. Several people can be seen standing next to railroad tracks in the foreground.

Black and white photograph, taken by Robert Merrill, looking southwest toward Cripple Creek, Colorado.

Black and white photograph, taken by Robert Merrill, looking southeast toward lakes. Likely taken near Pikes Peak, Colorado.

Black and white photograph showing view of Pikes Peak, Colorado below timber line.

Black and white photograph of several people at the top of Jupiter Terrace at Yellowstone National Park.

Black and white photograph of a group of seventeen people at Angel's Rest, Yellowstone National Park.

Black and white photograph of terraces from Point Lookout, Yellowstone National Park. A large group of people can be seen standing along one area.

Black and white photograph of terraces at Yellowstone National Park. Taken by Robert Merrill, looking southeast from hill.

Black and white photograph of terraces at Yellowstone National Park. Taken by Robert Merrill, looking south from hill.

Black and white photograph of Jupiter Terrace at Yellowstone National Park. Taken by Robert Merrill from below.