Interstate 35 in Oklahoma

Interstate 35 (I-35), in the US State of Oklahoma, runs from the Red River at the Texas border to the Kansas state line near Braman for a length of 236 miles (380 km). I-35 has one auxiliary route in the state, I-235, in the inner city of Oklahoma City. A second auxiliary route, I-335, is the designation for the Kickapoo Turnpike, although it will not meet I-35 until the southern extension of the turnpike to a junction with I-35 in Purcell is built. Excluding the Panhandle, I-35 forms the informal bisector for central Oklahoma, and along with US 81/US 283 in western Oklahoma and US 69/US 75 in the eastern portion, it provides one of the main north-south corridors through the state.

I-35 enters Oklahoma with U.S. Highway 77 (US-77) on a bridge over the Red River in Love County, south of Thackerville. US-77 splits off at exit 1 (Red River Road) but parallels the Interstate for its entire length in Oklahoma. I-35 maintains a near–due north–south course through Love and Carter counties. I-35 provides four exits to Ardmore. After leaving Ardmore, it has a brief concurrency with State Highway 53 (SH-53) and enters Murray County and the Arbuckle Mountains. I-35 then passes through Garvin County and the county seat of Pauls Valley. North of exit 79 (SH-145), I-35 enters McClain County. There, it passes through Purcell and Goldsby.

SH-9 joins the Interstate crossing over the Canadian River into Cleveland County, after which it splits off again. It then serves as a major urban Interstate in Norman and Moore. Between Norman and Moore, US-77 joins the Interstate again. It then enters Oklahoma City and Oklahoma County near milepost 120. Near downtown, I-35 splits off the mainline (which becomes I-235/US-77) and runs concurrent with I-40 for one mile (1.6 km) before splitting off to the north again. I-44 then joins I-35 between mileposts 133 and 137. In Edmond, US-77 joins the Interstate yet again.

At milepost 146, I-35 enters Logan County. It serves Guthrie at exit 153 (South Division Street), where US-77 splits off, and at exit 157 (SH-33/East Noble Avenue). The Interstate then crosses the Cimarron River into Payne County and enters Noble County shortly thereafter. It provides two exits to Perry and serves as the western terminus of the Cimarron Turnpike (US-412). After providing access to Tonkawa and Blackwell in Kay County, it crosses into Kansas, becoming the Kansas Turnpike.

Some sections of I-35 in Oklahoma City were already built in 1953 before the Interstate System was created. Following the passage of the Federal Highway Act of 1956 that created the Interstate Highway System, the Oklahoma Department of Transportation (ODOT) approved the location of the future Interstate north of Oklahoma City to the Kansas state line on a route previously surveyed by the Oklahoma Turnpike Authority for a proposed toll road. As a free road, the first five miles (8.0 km) of that section of I-35 were opened to traffic in 1958 from US-177 near Braman north to the Kansas border, where it continued as the Kansas Turnpike. This was followed by completion of the entire route from Oklahoma City northward to Braman by 1963 in several phases, including Edmond to Guthrie in 1960, Guthrie to Perry in 1961, Perry to Blackwell in 1962, and Blackwell to Braman in early 1963.^{[citation needed]}

To the south of Oklahoma City, I-35 was completed through Norman south to Purcell in June 1959. In Moore, it opened in two parts: the northern half, connecting Moore to Oklahoma City, opened in January 1960. The southern half, linking it to Norman, was opened to traffic in June 1967. The Moore–Norman segment was originally a four-lane section of US-77 built in 1951 that did not meet full Interstate Highway standards and included several at-grade intersections within the City of Moore, including some with traffic signals, and upgraded accordingly to include grade separations to bring up to full Interstate Highway standards and frontage roads to serve local traffic needs. Also not up to full Interstate Highway standards prior to 1967 was a section in the vicinity of Lindsey Street in the southern portion of Norman where another at-grade intersection still existed which dated back to the original highway's construction in the early 1950s—this was also brought up to full Interstate Highway standards in 1967 with the construction of interchanges on I-35 at Lindsey and a short distance to the south for the future SH-9 bypass that would be built around the southern side of Norman in the early 1970s.^{[citation needed]}

Further south, I-35 was completed from Marietta south to the Red River bridge in 1963, at which point a nearly 90-mile (140 km) gap of uncompleted Interstate would exist between Purcell and Marietta until the late 1960s with traffic continuing to be routed over paralleling US-77. This was in large part due to efforts of the towns of Wynnewood, Paoli, and Wayne fighting to keep I-35 as close as possible to US-77. This was successful due to a threat from Governor Henry Bellmon to build a toll road rather than I-35, and legislation preventing state funds for the Interstate from being spent if it were more than one mile (1.6 km) from the U.S. Highway.

The uncompleted gap of I-35 in Southern Oklahoma was narrowed in 1967 and 1968 when two sections were completed from US-70/SH-199 in Ardmore south to SH-32 in Marietta. In 1969, the section of Interstate bypassing Ardmore was completed north from US-70 two miles (3.2 km) to SH-142, and, the following year, 1970, brought the completion of I-35 from SH-7 near Davis south to Ardmore, at long last bypassing the winding section of US-77 through the Arbuckle Mountains. This stretch through the Arbuckles was particularly expensive and difficult to construct, taking almost two years and requiring the blasting and removal of 4 million cubic yards (3.1×10^⁶ m³) of rock. A few months later, in January 1971, I-35 was finally completed across the State of Oklahoma, when the remaining portions of the Interstate from Purcell to SH-7 near Davis were opened to traffic.