This afternoon I tweeted a picture of this treasure, found in the stacks of the University of New Mexico’s Centennial Science and Engineering Library:

Schulman E. Tree-ring hydrology of the Colorado River basin. University of Arizona; 1946.

Tom Swetnam, a friend who is the former director of the UofA Laboratory of Tree-Ring Research, recognized the name in the top-right corner: “Looks like that may be Florence Hawley Ellis’ personal copy of Schulman’s classic. From UNM Library?”, with a link to this autobiographical sketch:

I have directed field schools for the Univ. of New Mexico: 1948, 1949, and for 3 seasons in the early 1950s at San Gabriel del Yungue at San Juan, for 5 seasons in the 1950s and ’60s at Sapawe near El Rito, in 1971 at Tsama on the Chama, and since then for Ghost Ranch a number of sessions in Gallina mountain sites and in 1975 and 1976 on Gallina village sites. Before directing field schools I worked with the Univ. of Ariz. in excavations in summers and then with the Univ. of New Mexico in the Chaco where I spent 11 seasons at tree-ring collecting and research, excavations, and directing laboratory work.

Schulman’s work is a treasure for other reasons.

For The New Project, Eric Kuhn and I are tracing the evolution of our scientific understanding of the hydrology of the Colorado River Basin, and Schulman’s 1946 LTRR report is a key milestone in the expansion of the toolkit from the stream gauge record to include paleo-hydrologic reconstructions using tree rings.

I think (commenters who know this literature please jump in) that this is the first published tree-ring reconstruction of the flow of the Colorado River, though Schulman and A.E. Douglass, the founder of the Tree-Ring Lab and basically the whole founder of the dendro thing period, had done unpublished work during World War II to try to help the war effort by clarifying the flow of the Colorado River and therefore the hydropower available for the war effort. And in fact there’s a reference in this monograph to some work Douglass published in 1936 that may have taken a preliminary stab at a Colorado River flow reconstruction. So more to come.

I’m particularly loving this dive into the literature because my first book was about tree rings, and it’s always been one of my favorite bits of science. That this particular copy of Schulman’s work belonged to Florence Hawley Ellis, a pioneer, as well, makes it doubly cool.