Black and white lantern slide of boat traffic on the Xochimilco Canals in Mexico City.

Black and white lantern slide of boat traffic on the Xochimilco Canals in Mexico City.

Black and white lantern slide of boat traffic on the Xochimilco Canals in Mexico City.

Black and white lantern slide of the stepped sides of the Cuicuilco Pyramid taken from the side.

Black and white lantern slide of the steps of the Cuicuilco Pyramid taken from the base.

Black and white lantern slide of the unexcavated site of the Cholula Pyramid, with the Nuestra Senora de los Remedios Church in the background.

Black and white lantern slide of the Cholula Pyramid site, with a 132km marker next to the road side.

Black and white lantern slide of the Cholula Pyramid site, looking south.

Black and white lantern slide of Mexican landscape with the volcanoes Popocatepetl and Itzaccihuatl in the distance, looking southwest.

Black and white lantern (dark) slide of Mexican landscape with the volcanoes Popocatepetl and Itzaccihuatl in the distance.

Black and white lantern slide of the excavated terrace of the Cholula Pyramid site.

Black and white lantern slide view down Saltillo Falls, looking east.

Black and white lantern slide view of Saltillo Falls, looking west.

Black and white lantern slide of Saltillo, Mexico.

Black and white lantern slide of a stream of water along a street in Saltillo, Mexico.

Black and white lantern slide of two automobiles on dirt road near Saltillo, Mexico. One of the cars appears to be stuck and is surrounded by a small group of people.

Black and white lantern slide of Audie Merrill standing next to a sign reading "Tropico de Cancer" along a roadside in Mexico.

Black and white lantern slide of Fort Yellowstone, Wyoming.

Black and white lantern slide of rock formations at the Silver Gate site in Yellowstone National Park.

Black and white lantern slide of Roaring Mountain in Yellowstone National Park.

Black and white lantern slide of the Fish Pot hot spring in Yellowstone National Park.

Black and white lantern slide of Lena Merrill standing in front of a boulder in Yellowstone National Park.

Black and white lantern slide of a man leaning against a wall of stone at the East fork of Greenwood Creek.

Black and white lantern slide of a road sign for the "Home of the Minnesota Man," now known as the Pelican Rapids-Minnesota Woman, skeletal remains estimated at 8,000 years old.