In April 1925, an additional convict labor camp was established in Pushmataha County to assist with the construction of SH 10 across the Kiamichi Mountains.
On April 1, 1921, E. S. Alderman became the fifth Chief Engineer of the Department of Highways.
On April 1, 1929, House Bill 284 was passed, changing the number of Highway Commissioners from five back to three.
On April 1, 1930, the Commission called for the installation of modern accounting equipment, the Hollerith tabulating machines, to detail all department expenditures.
On April 1, 1936, the Highway Commission approved the designation of SH-39 from Purcell west
On April 2, 1917, President Wilson told congress that United States will enter into WWI.
On April 3, 1943, Senate Bill 183 was approved making it unlawful to construct or maintain any business or structure on the right-of-way on any State or Federal highway.
On April 4, 1934, major floods hit Western Oklahoma sweeping away bridges, roads, rails and houses. With US-66 and SH-14 blocked for days, Clinton residents were marooned.
On April 4, 1936, the first Federal Work Program grade crossing project in the state was completed on the M.K.T. Railroad southwest of Trail in Dewey County.
On April 4, 1987, the Transportation Commission elected Neal A. McCaleb as the 3rd Transportation Director.
On April 5, 1950, the Highway Commission instructed the Director of Highways to begin searching out locations for Interstate Highway routes between the Kansas line and Guthrie.
On April 5, 1971, the Highway Department began studying the state’s transit, airport and waterway needs and inventorying highway needs to comply with the Federal Aid Highway Act of 1970
On April 6, 1917, Congress passed the war declaration and President Wilson signed it.
On April 6, 1953, the Highway Commission designated SH 70E from the junction of US 70 east of Durant southeasterly to Albany.
On April 6, 1992, the Transportation Commission approved removing SH-74 designation from May Avenue and placing it on Lake Hefner Parkway on its completion.
On April 7, 1973, the final “east” segment of I-40, from old US-69 near Checotah east to Warner, was dedicated by Gov. Hall.
On April 8, 1929, John F. Rightmire became the eleventh Chief Engineer of the Highway Department.
On April 9, 1923, Senate Bill 349 was passed giving the Commissioner of Highways the ability to purchase right-of-way, prepare construction plans and appoint project engineers
On April 10, 1981, House Bill 1623 was approved authorizing the ODOT to acquire, construct, reconstruct, repair, operate and maintain railroad rights-of-way.
On April 10, 2009, Gov. Henry appointed ODOT Director Gary Ridley as the 6th Secretary of Transportation.
On April 11, 1962, the I-40 resurfacing project between US-281 in Caddo County and extending east to the Caddo/Canadian County line completed.
On April 12, 1943, Senate Bill 149 was approved authorizing the Highway Commission to construct and maintain flight strips, access roads and other necessary highways.
On April 12, 1945, a tornado hit the Highway Department’s Division 2 Office in Antlers. A contract to rebuild the facilities was awarded later that year.
On April 13, 1942, the first project to pave SH 49 between Cache and the Wichita Mountains Wildlife Refuge in Comanche County was awarded.
On April 14, 1936, the first inventory of all roads in Canadian County was completed. It was the first countywide road inventory to be completed in the state.
On April 14, 1960, the 4 ˝- mile surfacing project on I-35 from SH 33 south was complete in Logan County.
On April 15, 1936, the first inventory of roads in Grady and McClain Counties was completed and work began on the first Grady and McClain county maps
On April 15, 1939, House Bill 230 was approved, requiring the Highway Commission to maintain all roads connecting State and Federal Parks with highways and city streets.
On April 15, 1945, Heavy rains caused much of Eastern Oklahoma to flood, washing-out several state highway bridges and sections of pavement.
On April 16, 1936, the first inventory of all roadways in Kingfisher and Pottawatomie Counties was complete.
On April 16, 1945, House Bill 470 was approved levying an excise tax of two cents per gallon in order to provide additional funds to the State Highway Commission.
On April 17, 1931, House Bill 484 was approved transferring responsibility for registration of motor vehicles and the collection of tag fees to the Oklahoma Tax Commission
On April 18, 1989, the Oklahoma Senate adopted a concurrent resolution expressing support for the return of rail passenger service to Oklahoma.
On April 19, 1945, Senate Bill 297 was approved authorizing contracts suspended by federal agency orders during WWII be re-negotiated with the original contractor or cancelled by mutual agreement.
On April 20, 1948, Mr. Lundy, the new Tulsa Mayor, appeared before the Commission requesting the extension of Sapulpa Road and its reconstruction into a four-lane highway.
On April 21, 1989, House Joint Resolution 1029 was approved directing ODOT and several other state agencies to designate and promote old U.S. Route 66 as a historic route.
On April 21, 1989, the Centennial Expressway (I-235) was dedicated, linking the I-35/I-40 Jct. and I-44 near the State Capitol. The roadway opened to traffic the next day.
On April 22, 1931, House Bill 216 was approved authorizing the Highway Department to makes and enforce laws regulating the licensing of aircrafts and pilots.
On April 22, 1958, the first completed segment of interstate in Oklahoma was completed and dedicated on I-35 in Kay County
On April 23, 1923, the first bridge over the South Canadian River near Newcastle was completed. It replaced a toll ferry which operated intermittently.
On April 24, 1921, the Federal Aid project to construct a 6 miles of gravel road extending south from Lawton was completed.
On April 25, 1941, the first paving project on SH-34 from US-66 north to the Roger Mills County line was approved by the Highway Commission.
On April 26, 1939, House Bill 533 was approved authorizing the Highway Commission to purchase five existing bridges over the Red River from Texas.
On April 26, 1962, a project to surface I-35 from SH 15 in Noble County and extending north 10 miles into Kay County completed.
On April 26, 1963, a project to surface I-35 from the Red River bridge north 11 miles in Love County was completed.
On April 27, 1945, the Highway Commission submitted a proposal for 46 projects to repair flood damage and to prevent future damage on highways statewide.
On April 28, 1969, the Highway Department Commission Chairman appointed Commissioners Irish and West to a Survey Committee for the selection of a Director.
On April 28, 1973, the new Carl Albert Bridge across the Kiamichi River on SH 93 was dedicated in Choctaw County.
On April 29, 1969, the I-35 construction project beginning at the Carter County line and extending north 6 miles was completed in Murray County.
On April 30, 1947, Senate Bill 225 was approved creating the Oklahoma Turnpike Authority.
