Big Sur State Park: Where the Keeling Curve was Born

In early November of 2012, I spent a week camping at Molera State Park, at Big Sur, CA. MoleraDuring the trip south from Oregon, I did some online research and read an account of how the Keeling Curve came to be. The story was that Charles David Keeling, a graduate fellow at Caltech, developed some atmospheric testing equipment and went camping in 1955, somewhere along the lower reaches of the Big Sur River. It was evident from the reading that the data collected during that camping trip was something of a ‘Eureka!’ moment for Dr. Keeling. This meant that the first air samples, which helped the world to begin to measure the problem of excessive CO2 in our atmosphere, were taken at either Pfeiffer Big Sur State Park, or at Molera State Park. And, to me, this meant that Dr. Keeling did his work at one of my favorite places on Earth … possibly even where I was headed to camp.

Scripps Pier pic

The pier at Scripps, La Jolla, California.

I researched a bit further and found that Dr. Keeling’s son Ralph has followed his father, and today is a scientist at Scripps. Well, not just a scientist, but the Director at the CO2 Program at Scripps, and thus one of the world’s leading scientists studying the CO2 issue. I found Ralph Keeling’s email address and contacted him, asking if he could help me identify where the first air samples were taken, during the 1955 camping trip. Ralph kindly sent an email reply, then talked to his mother, and also consulted his father’s notes. In a subsequent email, he shared this one note:

“May 18, 55 Big Sur State Park, Air Samples, Camp 55, Site Half way down S.W. bank of river”

With this info, and with the additional details his mother recalled, it was clear the campsite was not at Molera, but was at Pfeiffer Big Sur State Park, and I hoped I could find it. I suspected, though, that the park had long ago been redeveloped, and I likely would not be able to identify the campsite. With a little luck, my fears were soon dashed.

Big Sur SP, campsite#55

Campsite #55 at Big Sur State Park

As it happens, my arrival at Big Sur was shortly after completion of a new vehicle bridge into the campground. In recent years, severe weather events had caused substantial erosion and flooding. The original bridge location was at a choke-point, that intensified flood damages. Also, over many decades, popular use of this park had caused substantial vegetation damage along the river banks. The state had decided to invest in improvements, to repair all this damage, and to ensure the park could withstand future severe weather events. I visited the campground that week, picked up a map showing the campsite numbers, and shot this photograph of campsite #55.

20121100.. Big Sur SP Campground mapMy timing was extremely lucky. How lucky? Well, just days after I shot the photo of campsite #55, the number was removed. With recent completion of the new bridge (crossing the river to the east of campsite #27 on this map), and with the permanent abandonment of a few campsites close to the river (the area marked ‘closed’ on this map), State Parks renumbered all the campsites.

The only remaining question, then, was whether this site had been renumbered in the past sixty years. I went to the small library in Big Sur and found some records. I made this copy:

The library search produced this copy of a 1999 ‘General Plan’ for redeveloping the park. Text identifies damaged vegetation and riparian areas, where some campsites were too close to the river. The severe weather events had not yet happened, thus the need for the new bridge was not yet identified.

1999 General Plan, Pfeiffer Big Sur SP (map)

OLYMPUS DIGITAL CAMERAI also found a kiosk near the Big Sur Lodge. It was in a hole, surrounded with new elevated trails. It looked like the plan was to remove the kiosk soon. I took photos, including closeups of a geologic map of the state park. 1950 geology map in Big Sur SP kioskThe most recent year on the geologic map was located in a statement that read: “Geology Surveyed by Gordon B. Oakeshott 1950”. The map showed the same campground and road configuration as was being redeveloped in 2012. It also showed many of the improvements constructed by the CCC in the 1930’s, which were now being repaired or removed. Here is a copy of the geologic map:

This is a closeup of the 1950 geologic map on display in the kiosk. The water samples were said to have been taken from the footbridge (see the line crossing the river, south of the word ‘Sites’ and north of the swimming pool). Camp#55 was located along the middle north-south road, just southeast of where the map says ‘Sawmill Flats’.


It appears that this 1950 map accurately reflects the campground configuration from 1955, when the first CO2 samples were taken. It also appears that state parks made no substantial changes until just the last few years. The new vehicle bridge was constructed at essentially the same location as the old footbridge, which is in close proximity to the former campsite #55.

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If you would like to know more about the Keeling Curve and Mr. Keeling’s story, please use this link:

Here are some other links…

WEB – March 2013, Andrew Molera camping trip
WEB – 2013 map of Pfeiffer Big Sur State Park (topo, color)
PDF – State Parks brochure with further info about Pfeiffer Big Sur SP