Bird’s Eye Views: Using Aerial Photographs for Historical Research

By Dewey Livingston, Map Archivist, Anne T. Kent California Room, Marin County Free Library

Black Mountain in West Marin in 1952. Anne T. Kent California Room Collection.

There are many avenues to travel in order to find historical information about your home, large property, neighborhood or wider community: ask a neighbor who has been there a long time; visit the library; join the variety of historical societies in the county; look for answers on the internet. Staff in the Anne T. California Room have offered research services and resources to the public for decades, and during the pandemic we have worked extra hard to answer all of your queries via phone and email.

One resource we find ourselves using more and more is our collection of historical aerial photos of Marin County. Homeowners, planners, historians, ranchers, environmental researchers: all can find interesting and even important knowledge in a clear aerial photo.

The California Room has archived a large set of aerial photography dating back to 1942, with good imagery from 1943, 1952, and the 1970s and 1980s. Another resource, the special collections library at UC Santa Barbara, has an extensive collection of aerial photography, including a wonderful set of Marin images dating from 1931: a flight along the 101 corridor from the future site of the Golden Gate Bridge all the way up to the future site of Terra Linda; the detail is terrific. Also, the public can download aerial photos of Marin (and anywhere in the United States) dating back to 1946 on the USGS member website called EarthExplorer.

An aerial photograph shows all sorts of interesting detail, and also gives a broader view of land changes over time. The photographs are usually made for mapping purposes, with a highly technical calibrated camera — utilizing large format films typically 9x9 or 10x10 inches — loaded in an airplane and aiming straight down to the ground from various elevations. These photo sets were used to make topographic maps and for county and agricultural planning. In this article we will share some examples of aerial photography’s many uses to the historian, scientist, planner, and resident.

The following series of three images were taken over Santa Venetia in 1946, 1952, and 1960. They depict the urban growth from ranch and wetlands to suburban community.

In 1946, North San Pedro Road runs diagonally from the bottom of the image to the upper right corner; Santa Margarita Island is in the center left. The area is still largely rural, with some housing being built east of the island. The small airport at Santa Venetia, merely a bulldozed dirt strip, is at top right. Anne T. Kent California Room Collection.

By 1952 the main Santa Venetia housing tract has almost surrounded Santa Margarita Island, but the airport is still there and more fully developed. Venetia Valley School has been built, bottom center left. The marshland at center left and upper left has been cultivated as hayfields. A wide fire road has been cut into the mountain. Anne T. Kent California Room Collection.

In 1960 much of the Santa Venetia housing tract has been built, and the airfield is gone. A new housing tract adjacent to the school has been built, and the hayfields are fallow. Anne T. Kent California Room Collection.

The following single view of eastern San Rafael was taken in 1952. The town is beginning to expand into the marshlands south of San Rafael Creek, which has been transformed into a navigable canal. This was of interest to a researcher interested in the changing wetlands of the bay.

This view of San Rafael in 1952 illustrates the urban growth that was happening all over California after the war. Highway 101 is in its early stages as a freeway, and the distinctive diagonal patterns of highway and two crossing rail lines still show in the left half of the image. Simms Island remains intact in the lower center, soon to be blasted away for the southern Bellam Blvd. neighborhood. The Canal area on the right half is yet to be developed, still largely salt marsh and field. In the far upper right corner we can see the fresh construction of Sea Way and Summit Avenue and the future site of the Marin Yacht Club, and at left the expanding Bret Harte neighborhood. Anne T. Kent California Room Collection.

A researcher recently asked about changes in San Geronimo, and the two following images show that small town going through a few changes.

In 1952 the old Sir Francis Drake Highway weaves through the valley and over San Geronimo Creek on a bridge (center), with the turnoff towards Nicasio lined with trees heading north. The Roy Ranch is seen on the right. The old Northwestern Pacific Railroad grade, abandoned since 1933, is visible crossing the scene, passing through Roy’s fields in the upper right and into San Geronimo Station, where the former depot grounds form a triangle. Anne T. Kent California Room Collection.

By 1976 the scene is changed, not with urban growth but with a new modern highway cutting through the valley and a golf course on the former ranch pasture. The clubhouse and parking lot are seen at upper right, and the old Roy ranch now faces new golfing greens and artificial ponds. The wide highway has obliterated the old railroad grade, the old road was renamed San Geronimo Valley Drive, and there is a handful of new houses. Anne T. Kent California Room Collection.

Often the aerial imagery is helpful to those studying environmental changes in the county. A group recently inquired about Laguna de San Antonio at the northern county line, and we were able to supply a series of images showing the evolution of this natural body of water. The water in the laguna subsides as the summer progresses, to be refilled with winter rains.

The Laguna in 1952, showing the farming that had been a traditional use since the 1860s, when Chilean hop growers utilized the shrinking shoreline for cultivation. (Chileno Valley got its name from these early immigrants.) Dairy ranchers continued the tradition, planting feed crops in a similar manner to the early farmers, seen in the cultivated edges and bottom of the lake. Anne T. Kent California Room Collection.

Sometimes the imagery is interesting both for history and artistry. The following 1952 images show an interesting landscape altered by humans.

When Marin Municipal Water District prepared Lagunitas Canyon for its new reservoir, to be named Kent Lake, the to-be-drowned area had to be logged and cleared (top and center, in 1952). The district also allowed the surrounding redwood forest on the east side of Bolinas Ridge to be logged, leaving a complicated web of logging roads scarring the landscape. In the upper right corner, vestiges of the intense 1945 fire can be seen. Anne T. Kent California Room Collection.

The Gallagher family cut their hayfields in distinctive — if not artistic — patterns on Bull Point at Point Reyes. Courtesy of USGS.

Aerial photography provides fascinating bird’s-eye-view images that can provide hours of exploration and enjoyment. Sometimes the feelings turn sad as we see natural beauty disappear under development, but we can also learn a lot about our surroundings and how the landscape of Marin has been manipulated, and also find some of those special places that have barely changed at all.

Editor’s note:

The Anne T. Kent California Room is currently still closed to visitors, in part due to temporary lack of staffing. To contact us for research assistance, please visit our website, including our About Us page. You can also search or browse our extensive online digital archive.