1. Biography / bibliography, miscellaneous correspondence
  2. Biography / bibliography, miscellaneous correspondence, Obituary
  3. Pictures, personal, newspaper articles
  4. Alice Eastwood material, miscellaneous correspondence
  5. Galapagos Islands, pictures, Crocker Expedition of 1932
  6. St. Hilary's; Landmarks Soc., birthday photographs
  7. St. Hilary's Botanical Pres.
  8. Sierra Club; Botany 1940-1942, 1946-1948; Misc. notes and jottings
  9. Sierra Club; Base Camp 1948-49, S.C. Yodeler
  10. Sierra Club notes, bulletin
  11. Manuscript for "Sierra Ferns"
  12. Western Botany 1949-59, 1970-73, Finan. 1949-70
  13. Western Botany Vol. III, No. 3 1953- Misc.
  14. Western Botany 1960-69, Misc. manuscripts and letters
  15. Miscellaneous publications 1929-1941; bibliography #1-150
  16. Miscellaneous publications 1942-1953; bibliography #155-341
  17. Miscellaneous publications 1954-1971; bibliography #349-485
  18. Miscellaneous publications 1972; bibliography #490-501
  19. Publications, "Marin Flora" lists, letters, reviews
  20. Publications, "Marin Flora" revised manuscript
  21. "Marin Flora" photographs, correspondence with the UC Press
  22. Manuscript - supplement of Vascular Plants of Monterey County
  23. Vascular plants of Monterey County, manuscript, lists
  24. Studies in Phacelia, manuscript, publications 1943-1945
  25. Phacelia articles, American Midland Naturalist, Sept. 1946
  26. "California Flora", manuscript, correspondence
  27. "Butterfly Valley", manuscript, proof
  28. C.A.S. publications
  29. Assorted manuscripts
  30. Rancho Santa Ana "Plants of Toiyable Mts.", 1952 Echeveria
  31. Manuscript material for "Flora of San Francisco"
  32. Manuscript "Flora of San Francisco"
  33. "Flora of Lassen Park"; "Flora of San Francisco"
  34. Correspondence 1930-75 A
  35. Correspondence 1930-41 B
  36. Correspondence 1942-48 B
  37. Correspondence 1948-59 B
  38. Correspondence 1960-75 B
  39. Correspondence 1930-43 C
  40. Correspondence 1944-57 C
  41. Correspondence 1958-72 C
  42. Correspondence 1973- C
  43. Correspondence 1930-69 D
  44. Correspondence 1970-74 D
  45. Correspondence E
  46. Correspondence F
  47. Correspondence 1936-69 G
  48. Correspondence 1970-74 G
  49. Correspondence 1930-37 H
  50. Correspondence 1939-49 H
  51. Correspondence 1950-59 H
  52. Correspondence 1960-66 H
  53. Correspondence 1967-75 H
  54. Correspondence 1930-75 I-J
  55. Correspondence 1930-49 K
    55a. Correspondence 1950-75 K
  56. Correspondence 1930-69 L
  57. Correspondence 1970-75 L
  58. Correspondence 1930-46 M
  59. Correspondence 1947-54 M
  60. Correspondence 1955-66 M
  61. Correspondence 1967-75 M
  62. Correspondence N
  63. Correspondence O
  64. Correspondence 1930-46 P-Q
  65. Correspondence 1947-61 P-Q
  66. Correspondence 1962-75 P-Q
  67. Correspondence 1930-59 R
  68. Correspondence 1960-75 R
  69. Correspondence 1930-41 S
  70. Correspondence 1942-50 S
  71. Correspondence 1951-62 S
  72. Correspondence 1963-75 S
  73. Correspondence 1930-63 T
  74. Correspondence 1964-75 T
  75. Correspondence 1930 U-V
  76. Correspondence 1966-75 W
  77. Correspondence 1947-65 W
  78. Correspondence 1931-46 W
  79. Correspondence 1930 X,Y,Z
  80. Wassman Journal of Botany
  81. Wassman Journal of Botany
  82. Folder with lists of native plants, California Botanical Club trip to Yosemite, 1980, misc.
  83. Correspondence before becoming Curator of Botany at C.A.S.
  84. Western Botany - correspondence, bills, etc.
  85. Correspondence 1976-1982
  86. Norden - 1943, Tuolome Meadows Olancha trip 1950, MS San Joaquin trip 1958, Kern Plateau 1966
  87. Sonoma County / Salt Point State Park 1970, Plant list Sea Ranch Plants / Wells and Kektner Sonoma County / Pepperwood 1985, etc.
  88. Correspondence 1976-1980
  89. Correspondence
  90. Sierra / Central Valley
  91. Sierra / Central Valley
  92. Sierra / Central Valley
  93. Sierra / Central Valley
  94. Sierra / Central Valley
  95. Sierra / Central Valley
  96. Sierra / Central Valley
  97. Sierra / Central Valley
  98. Sierra / Central Valley
  99. Sierra / Central Valley
  100. Sierra / Central Valley
  101. Sierra / Central Valley
  102. Sierra / Central Valley
  103. Sierra / Central Valley
  104. Sierra / Central Valley
  105. Negatives
  106. Galapagos
  107. Galapagos manuscripts, fieldnotes
  108. Copies of Howell correspondence to others (alpha); correspondence to and from Shevock, Tiehm, Margaret Williams.
  109. Gordon True ms.; misc. correspondence
  110. Newspaper clippings; other stuff
  111. Sue Taylor correspondence; Flora of Butte Co.
  112. Gordon True- Nevada Co. checklist; unopened 3rd class mail from 1992; reprints; misc. correspondence
  113. Butte Co. Flora
  114. 60th Anniversary celebration"; correspondence; "non-botanical memorabilia"
  115. Card files
  116. "Second Sierra Catalogue" Paste-ups; "Base Camp Botany" notebooks; Carex field notes, references, manuscripts; South Coast Ranges flora: plant lists, manuscripts, articles; Manuscripts, notes, lists, pictures, etc. re: Carex, Galium, Pogogyne, lichens, Douglas specimens.
  117. Carex publications; Kern Plateau and Alabama Hills plant lists, correspondence; California Floras south to San Diego: manuscripts and correspondence; North Coast Ranges-Cascade Range: plant lists, articles, publications; Sierra Flora: photos, notes, plant lists, misc.
  118. Sierra: Research projects, tree plantings, misc.; Sierra books and pamphlets; Butte, Sierra, Plumas, Lassen Counties: articles, plant lists, publications, misc.; Nevada County plant lists, publications, misc.; Placer County to Yosemite Region plant lists, publications, misc.; South of Yosemite reports, plant lists, publications, misc.; Central Valley plant lists, publications, correspondence, misc.
  119. Kern County, Owens Valley, Desert Ranges notes, plant lists, reports, publications, misc.; California: pamphlets, plant lists; Marin County / Tiburon: Landmark Society articles, publications, misc.; Rare and Endangered Plants / California endemics, etc.: reports, lists, misc.
  120. Nevada Flora- Washoe County (Peavine, Little Valley): articles, lists, publications, misc.; Trips and Travel; Poisonous Plants, Trees, Weeds; Weeds, Nonsense & Miscellany; California Botanical Club lists and programs; California Native Plant Society and Rare Plant Lists.
  121. California Native Plant Society: newsletters; Nevada Native Plant Society: newsletters, checklists, misc.; Oregon Rare and Endangered Plant Species Task Force; Waucoba News; Lowell Ahart Plant Journals; Peter Raven article; C.P. Smith Index
  122. Varius Publications: Twisselmann, E. C., Stuckey. Ronald L., Howell, J. T., Howell-Lessingia; Howell-Biography, etc.; Misc.
  123. Phacelia species notes, misc.; Other species manuscripts, notes; Systematics Miscellaneous; Miscellaneous publications by Howell.
  124. Miscellaneous
  125. Newspaper clippings, brochures, newsletters, invitations; a manuscript
  126. Booklets, clippings, maps; 3 folders of Margaret Williams correspondence
  127. Clippings, Base Camp Botany 1940-1949; Contribution to Flora of Sierra Buttes (Lowell Ahart 1983)

Oversize materials (drawings, certificate, map, photograph) in flat files