Among the many documents that account for the US presence at the Baltra (or South Seymour) Island's military base between 1941 and 1946 are photos of the soldiers who were stationed there.

A series of these photos, belonging to Dr. Alfred Croneis and relating to life in Baltra, were donated by his widow, Catherine, to the CDF Library, Archive & Museum. Taken around October 1943, they reflect not only part of the reality of the military base, but also the tours of the troops to other islands and their aerial cartography and surveillance tasks.

The collection includes slides with cardboard frames, and the only slides with metal frames in the CDF Archive — frames sadly remembered for unsettling slide projectors with their excessive weight and thickness.

Among the contents of the slides are black and white images of life on the base, especially next to large planes, and color photos showing aerial views of different points of the islands (taken from those same planes), and visits of the troops to other points of the archipelago.

Among these visits, a subseries tells of a trip to Santa Cruz Island, where a group of soldiers contact the Icelandic settler Walter Finsen and some inhabitants of an incipient Puerto Ayora.

In addition, the series includes one of the few existing images of the diplomas of the "Order" of Baltra.

The collection is interesting for showing the life of the military, their social interactions with the island settlers, and their exploration of the Galapagos space beyond the borders of little Baltra.