| Claims filed for placer mining around Briceland | The Humboldt Times | MF 10 | 9/20/1911 | 1 | 1 | Legal Notice | Briceland | Businessman, Claims, Placer Mining |
| Claire Engle comments on Shasta water usage | Humboldt Times | MF 10 | 8/3/1951 | 1 | | Water Usage | Shasta | Shasta, Water Usage |
| Clark School at Table Bluff | Humboldt Times | MF 10 | 1/23/1948 | 1 | 5,6,7 | Photo | Table Bluff | Clark School, Table Bluff, Coast Guard Lighthouse |
| Clarke Museum formally dedicated today | Humboldt Times | MF 10 | 8/21/1960 | 22 | 4 & 5 & 6 & 7 | Dedication | Clarke Museum | Clarke Museum, Dedication |
| Classification Of the 1046 miles of county roads is now in process | Humboldt Times | MF 10 | 1/21/1948 | 1 | | Road classification | Humboldt County | County Roads, Classif. |
| Classified ad states for your Convenience | Humboldt Times | MF 10 | 7/31/1938 | 16 | 4 | Ad | Big Lagoon | Humboldt Time, Classified Ad |
| Classroom equipment being moved | Humboldt Times | MF 10 | 9/6/1928 | 2 | | Classroom equipment | Arcata Union High School | Classroom Equipment, Arcata Union High School |
| Clearing of land for streets | Humboldt Times | MF 10 | 6/10/1923 | 9 | | Land | Eureka | Land, Bound, Acres, Clearing, Stream, Streets, Tract |
| Clerk ordered to advertise for bids of bridge over Salt river | Daily Humboldt Times | MF 10 | 5/6/1886 | 3 | 2 | BOS proceedings | Salt River | Bos Proceeding, Bids, Bridge |
| Clerks of county assessor have settled offices previously by Sheriff | Humboldt Times | MF 10 | 7/29/1909 | 5 | 7 | Building use | Eureka | Eureka, New County Jail, County Assessor |
| Cloverdale to Hopland section | Humboldt Times | MF 10 | 8/3/1934 | 2 | 3--4 | Highway 101 | Cloverdale Hopland | Highway, Photo, Cloverdale, Hopland, Road |
| Cloverleaf interchange in Arcata opened Friday | Blue Lake Advocate | MF 2191 | 10/7/1965 | 8 | 3 | Road opening | Arcata | Arcata, Cloverleaf Interchange |
| Club Opposes Diversion of River water by Snow Mtn Water & Power Company | Humboldt Times | MF 10 | 4/23/1926 | 9 | 6 | Water use | Eel Eureka | Opposes, Application, Eel, Rr |
| Clyde E. Kennedy arrived yesterday to inspect the field of operation. | Humboldt Times | MF 10 | 9/26/1934 | 2 | 5 | Site details | | Inspection, Dam, Project |
| Co. Airport in McKinleyville | Humboldt Times | MF 10 | 8/4/1942 | 9 | 6 | Construction projects | McKinleyville | Airport, Construction, Plants, Railways |
| Coast and Garberville wagon roads being pushed through | Daily Humboldt Times | MF 10 | 8/6/1878 | 3 | 2 | Wagon roads | Garberville Coast | Garberville , Wagon Road |
| Coast Artillery Corps perfect military maps of this area | Humboldt Times | MF 10 | 5/6/1909 | 1 | 7 | Military Maps | | Coast Artillery Corps, Military Maps, Lts. Geo. Ruhlen & Edwin Pritchett |
| Coast hit by severe weather | Humboldt Times | MF 10 | 12/11/1937 | 1 | | Weather | | Coast, Heavy Downpour, Major Floods |
| Coast Pacific Lumber Company | Humboldt Times | MF 10 | 7/6/1952 | 8 | | Aerial Photos | Eureka | Eureka, Coast Pacific Lumber Company |
| Coastal Regions demand | Humboldt Times | MF 10 | 9/26/1952 | | | Public outcry | | Coastal Regions |
| Coastline | Humboldt Times | MF 10 | 8/14/1960 | 17 | | Photo | Shelter Cove | Shelter Cove, Photo |
| Cock Robin bridge still stable, Summer bridge washed out | Humboldt Times | MF 10 | 11/17/1937 | 7 | 6 | Bridge damage | Cock Robin bridge Weymouth Eel River | Bridge, Stable, Replaced |
| COE asked Congress authorize for $2.65 million dollar project | Humboldt Times | MF 10 | 8/28/1962 | 1 | | Project authorized | | Coe, Congress, $2.65 Million Project, Charles Sheller |
| COE issued invitations for bids to drill holes | Blue Lake Advocate | MF 2191 | 9/30/1965 | 1 | 4 | Land work | Redwood Creek | Coe Issued Invitations, Investigating Soil Foundations |
| COE studying entrance to Humboldt Bay | Humboldt Times | MF 10 | 10/9/1960 | 2 | | Lines of the Times ( Oct. 8, 1881) | Humboldt Bay | Coe, Studying, Humboldt Bay Entrance, Colonel Medall |
| COE to survey erosion of Eel bank | Humboldt Times | MF 10 | 3/1/1953 | 21 | 2 | Survey Work | Sandy Prairie | Coe Survey, Erosion Eel |
| COE will begin survey of local rivers | Humboldt Times | MF 10 | 5/18/1929 | 1 | 7 | Survey Work | Mad River Klamath River Eel River | Coe, Survey |
| Col. Biddle inspected dredging work and looked at the rock quarry for jetties extending | Daily Humboldt Standard | MF 9 | 7/18/1908 | 3 | 3 & 4 | Inspecting work | Humboldt Bay Trinidad Jacoby Creek | Col. Biddle, Inspecting, Dredging, Jetties Extend |
| Col. Mendell survey bay | Daily Humboldt Times | MF 10 | 9/11/1880 | | | New report | Humboldt Bay | Humboldt Bay, Survey By Col. Mendell |
| Cold spell in January 1888 with 6 feet on the ground for a week | Humboldt Times | MF 10 | 1/10/1937 | 2 | 5 | Weather | Ricks Prairie | Cold Spell, January, Ricks Prairie |
| Cold weather, low in 30 years | Daily Times | MF 10 | 2/6/1883 | 3 | 1 | Weather | | Dr. Clark, Cold Weather, 21F |
| Collier Tunnel | Bicentennial Edition | MF 10 | 1776-1976 | 47 | | Road work | Collier Tunnel | Collier Tunnel, Oregon Mtn |
| Collier Tunnel dedication | Humboldt Times | MF 10 | 7/14/1963 | 6 | 3 & 4 | Dedication | 199 | Collier Tunnel, 199, Randy Collier |
| Colonel D.O. Elliot in charge of 12-15 mapping party 1916 | Humboldt Times | MF 10 | 5/5/1950 | 1 | | Land survey | Trinity headwaters Upper Mattole | Colonel D.O. Elliot, 12-15 Man Mapping Party 1916, Trinity Headwaters, Upper Mattole |
| Column by W.N.S. on Occidental Pavilion | The Humboldt Times | MF 10 | 10/25/1940 | 4 | | Column | | Column, W.N.S. , Occidental Pavilion |
| Column on early logging railroads | Blue Lake Advocate | MF 2191 | 12/9/1965 | 5 | 2, Susie Baker Foundation | Logging railroad | Arcata | Early Logging Railroads, Arcata, Mrs. Gertrude Connick |
| Column on individual involvement | Humboldt Times | MF 10 | 4/15/1951 | 5 | 6 | Column | | Column, Individual Involvement |
| Column on Isaac Collberg life | Humboldt Times | MF 10 | 8/30/1961 | 11 | | RFD by Genzoli | Orick Arcata | Column, Isaac Collberg, Maxwell Car, Articles |
| Commissioner, C.F Stern | Humboldt Times | MF 10 | 6/2/1918 | 4 | | Editorial | | Highway Opening, C.F. Stern Commissioner |
| committee formed new dump site | Humboldt Times | MF 10 | 8/31/1926 | 11 | | land use | Bayside Brainard | New Dump Site Brainard |
| Committee leaves for hearing | Humboldt Times | MF 10 | 7/29/1926 | 7 | | Hearing | Ukiah | Hearing, Committee, Water Diversion |
| Committee Report on Trinity River Diversion Project | Humboldt Times | MF 10 | 10/28/1951 | 10 | | Committee Report | Trinity River | Committee Report, Trinity River Diversion Project |
| Common Council approved resolution committee be formed for well | Daily Humboldt Times | MF 10 | 4/7/1878 | 2 | 2 | Resolution | | Common Council, Artesian Well, A.W. Randall |
| Common Council Meeting | Daily Humboldt Times | MF 10 | 8/4/1878 | 3 | 3 | Meeting | | Common Council, Surveyor |
| Common Council passed resolution City Marshall contract tree planting | Daily Humboldt Times | MF 10 | 1/6/1878 | 3 | 2 | Resolution | Eureka | Common Council, Eureka, Gum Trees |
| Complaint about Kitchen drains | Daily Times | MF 10 | 3/16/1883 | 3 | 1 | Complaint | | Kitchen Drains |
| Complaints of dam owned by local Indians | Daily Humboldt Times | MF 10 | 7/26/1878 | 3 | 2 | Dam complaints | Eel Ellery Place | Ellery Place, Complaints Of Dam, Local Indians |
| Completion of an oil storage tank | Humboldt Times | MF 10 | 8/18/1923 | 2 | | Infrastructure | Eureka | Storage, Tank, Shell, Oil |
| Completion of new Dr. Everett Hunt Orthodontic building | Humboldt Times | MF 10 | 10/5/1949 | 6 | | Photo & Article | | Dr. Everett Hunt Orthodontic Building |
| Completion of new road from Hoopa to Weitchpec | Humboldt Times | MF 10 | 9/21/1923 | 2 | | Infrastructure-road | Hoopa Weitchpec | New Road, Hoopa |
