The Connecticut Geological Survey has a collection of 34 out-of-print Biennial Reports of the Commissioners of the State Geological and Natural History Survey to the Governor and State Legislature of Connecticut. These historic reports chronicle the legacy and evolution of the State Geological and Natural History Survey of Connecticut from its inception in 1903 until it became an entity of the state environmental agency in 1971.  These reports, ranging from 11 to 40 pages, are valuable to science historians, academic scholars, geoscience professionals, and public policy experts.

Content of the reports includes a description of Survey work during the period of the report, relevant lists of publications and water supply papers, publications in press, investigations in progress, cooperation with the United States Geological Survey and academic institutions, financial ledgers associated with contract scientists, appropriations, plans for future work, and legislation. There are separate sections within the geology program area for mapping, mineral resources, supported professors and graduate students. Within the natural history program area there are separate sections which variably include botany, entomology, ecology, and zoology.

Biennial Report	Subject Year
First  (Bulletin 1)	1903-1904
Second (Bulletin 9 )	1905-1906
Third (Bulletin 12)	1907-1908
Fourth (Bulletin 17)	1909-1910
Fifth (Bulletin 21)	1911-1912
Sixth (Bulletin 25)	1913-1914
Seventh (Bulletin 27)	1915-1916
Eight (Bulletin 28)	1917-1918
Ninth (Bulletin 32)	1919-1920
Tenth (Bulletin 35)	1921-1924
Twelfth (Bulletin 38)	1925-1926
Thirteenth (Bulletin 45)	1927-1928
Fourteenth (Bulletin 50)	1929-1930
Fifteenth (Bulletin 52)	1931-1932
Sixteenth & Seventeenth (Bulletin 59)	1933-1936
Eighteenth & Ninteenth (Bulletin 62)	1937-1941
Twentieth (Bulletin 66)	1941-1942
Twenty-First (Bulletin 67)	1943-1944
Twenty-Second (Bulletin 71)	1945-1946
Twenty-Third (Bulletin 72)	1947-1948
Twenty-Fourth (Bulletin 79)	1949-1950
Twenty-Fifth (Bulletin 82)	1951-1952
Twenty-Sixth (Bulletin 83)	1953-1954
Twenty-Seventh (Bulletin 85)	1955-1956
Twenty-Eigth (Bulletin 90)	1957-1958
Twenty-Ninth & Thirtieth (Bulletin 95)	1959-1962
Thirty-First (Bulletin 98)	1963-1965
Thirty-Second (Bulletin 100)	1965-1967
Thirty-Third (Bulletin 102)	1967-1969
Thirty-Fourth (Bulletin 104)	1969-1971