Series 301 Access Restricted
Series 302 Board of Supervisors: Records of Commission on Government, 1926-1937 (bulk 1936-1937)
Series 303 Elizabeth Shepard Lough Papers: Commission on Government, 1914-1937 (bulk 1934-1936)
Series 304 Alfred B. Del Bello Subject Files, 1969-1981
Series 305 Westchester 2000 Commission and Affiliated Organizations, 1984-1995
Series 306 Government Videos and DVDs Collection, 1980s-present
Series 307 Department of Correction Scrapbook, 1986-1989
Series 308 Board of Legislators Board Meeting Packets, 1970-2000
Series 309 Department of Correction Historical Records Collection, 1903, 1981, 1995
Series 310 Jail Blotter Books, 1903-1973
Series 311 Indexes to Jail Blotter Books, 1914-1938, 1941-1943, 1946-1974
Series 312 Planning Department Maps Collections, 1943-present
Series 313 DPW Parks and Parkways Acquisition Maps, c.1920s-1970s (bulk 1920s-1930s)
Series 314 Parks Department Oversized Materials Collection, c.1896-1962 (gaps)
Series 315 Westchester County Atlases Collection, 1867-1984 (gaps)
Series 316 Sanborn Maps and Atlases Collection, 1887-1939 (gaps)
Series 317 Planning Department Correspondence and Memos, 1976-1978
Series 318 Charles Point Resource Recovery Facility Photograph Album, 1984
Series 319 Colonial and Revolutionary War Reference Collection, 1853, 1951, ca. 1990s
Series 320 Westchester Cross County Parkway Authority Calendars and Minutes, 1944-1948
Series 321 Planning Department Correspondence, Memos and Speeches, 1944-1971
Series 322 Parks Department Contact Sheets / Prints Collection, ca. 1930s-2006 (bulk 1980s-2006)
Series 323 Parks Department Slide Collection, ca. 1973-2007 (gaps)
Series 324 Veterans Peddler Applications, 1955-1970, 1974-1983
Series 325 Law Department Historical Records, 1915-1967
Series 326 Planning Department Aerial Photographs
Series 327 Supreme Court Cases Registers, 1847-1911
Series 328 Parks Department Marketing/Public Relations Subject Files 1967-2005 (bulk 1980s-1990s)
Series 329 New York State Laws, 1813-1815, 1850, 1899-1900, 1939
Series 330 Office of Communications Newspaper Clipping Files, 1997-2009 (gaps)
Series 331 Health Department Press Releases, 1994-2006
Series 332 Division of Public Health Education and Information Materials, 1984-2006 (bulk 1990s-2003)
Series 333 Good Roads Records, 1901-1917
Series 334 Personnel Office Scrapbooks, 1947-1971
Series 335 Finance Department Scrapbooks, 1930-1950
Series 336 Special Proceedings Registers, 1817-1911 (bulk 1847-1911)
Series 337 County Court Registers, 1847-1911
Series 338 Planning Board Meeting Materials, 1939-1992 (bulk 1969-1992)
Series 339 Budget and Appropriations Committee Meeting Minutes, 1926, November 1928-1971, 1974-1976
Series 340 Board of Legislators News Clippings and Press Releases, 1983-2006 (bulk 1990-1998, 2001-2005)
Series 341 County Court Case Index, 1868-1933
Series 342 County Court Minutes, 1853-1911
Series 343 Naturalizations – Court Orders, July 1929-December 1986
Series 344 Supreme Court Minutes, 1869-1916 (bulk 1869-1911)
Series 345 Supreme Court Equity Judgments, 1830-1912
Series 346 County Executive Subject Files, 1933-1973 (bulk 1939-1972)
Series 347 Parks, Recreation and Conservation Biodiversity Studies, 1977-2010 (bulk 1990s)
Series 348 County Court Case Files, ca. 1847-ca. 1911
Series 349 Special Proceeding Case Files, ca. 1847-1922
Series 350 Park and Parkway Property Acquisition Deeds, ca. 1910s-1930s