The Saguaro Official National Park Handbook from 1985 is largely the same as the Saguaro National Monument, Arizona - Natural History Series - 1972.

This Handbook is based on the 1972 Handbook with only a few notable changes.

The maps in the middle of the guide are updated, I assume to better reflect the 1985 boundaries.

A change towards the end of the Handbook is more interesting. In the section titled 'the impact of man' (added in the 1972 version, not present in the 1957 version) the 1972 version features a picture of a bulldozer clearing Saguaros - a bold, brutal and startling image that I believe emphasizes the message of the text on the next page (the text is the same in both versions):

These desert and mountain environments—which once seemed secure, needing only the continued protection afforded by their status as a national monument—are increasingly imperiled by the works of man. As the city of Tucson sprawls in all directions, the monument's two divisions, islands in an encroaching sea of civilization, must withstand ever-accelerating hazards. Vandalism takes an increasing toll of the saguaros; housing developments creep toward the monument borders. Smog drifts over the fragile plant communities, threatening to choke them—as the polluted air from Los Angeles is already strangling forests in the distant San Bernardino Mountains.

In the 1985 version the bulldozer is gone - in it's place is the photo of a stunning old Saguaro that was featured as the inside cover of the 1972 version...

Older versions:

• Saguaro National Monument, Arizona - Natural History Series - 1972
• Saguaro National Monument, Arizona - Natural History Handbook Series No. 4 - 1957

All three versions can be found on the National Park Services Handbooks (Natural History Handbooks Page).