# Cimarron Turnpike

The Cimarron Turnpike is a controlled-access toll road in north-central Oklahoma. The route travels 67 miles (108 km), from an interchange with Interstate 35 (I-35) north of Perry, to Westport, just west of Tulsa. The route also consists of a 7.2-mile (11.6 km) spur which runs from the mainline southwest to an interchange with U.S. Route 177 (US 177) north of Stillwater.
The entirety of the Cimarron Turnpike is concurrent with US 412 except for the Stillwater spur. At either end of the Turnpike, US-412 begins (or ends, depending on direction) a concurrency with US-64.
The Cimarron Turnpike opened to traffic in 1975. The US 412 designation was applied to the Cimarron Turnpike in 1988.

## Route description

The Cimarron Turnpike, carrying US-412, passes through Noble, Payne, and Pawnee Counties. The highway heads east from I-35 to its first interchange, Exit 2, which provides access to US-77. The first mainline toll plaza is just west of Exit 15, a cloverleaf interchange with no straight-line ramps (forcing all traffic getting on or off to pass through the toll plaza) connecting the turnpike to US-177. East of the US-177 interchange, the highway curves to the south, crossing Black Bear Creek. US-412 then meets US-64 once again, interchanging with it at Exit 23 east of Morrison. The turnpike then turns back east, with a spur route (accessible only from the westbound turnpike) branching off to the southwest toward Stillwater. The Lone Chimney service plaza, a twenty-four-hour concession area, is located in the median of the turnpike east of the interchange with the spur.
South of Pawnee lies an interchange (Exit 37) with SH-18. Just south of Hallett, a second mainline toll plaza sits just west of the SH-99 interchange; again, this interchange is a cloverleaf interchange with only loop ramps. The turnpike's final exit is Exit 60, a partial interchange with SH-48 southeast of Cleveland. The missing movements are provided by US-64, the northern terminus of SH-48, which merges with US-412 as the Cimarron Turnpike ends. The two routes continue east as the Keystone Expressway, a freeway that connects the turnpike to downtown Tulsa.

## History

The Cimarron Turnpike opened to traffic on May 16, 1975, and cost $74 million to construct. On February 1, 1988, the Oklahoma Transportation Commission unanimously approved an extension of US-412 from its original western terminus at Walnut Ridge, Arkansas to Woodward, overlapping the Cimarron Turnpike.

## Tolls

As of 2022, passengers of two-axle vehicles (such as cars and motorcycles) pay a total of $7.45 to travel the entire length of the Cimarron Turnpike. Tolls vary based on the entrance and exit used. The turnpike accepts OTA's Pikepass transponder system as an alternative to PlatePay payment. Pikepass customers receive discounted toll rates; the Pikepass rate for the full length of the Cimarron is $3.30.
As of August 30, 2022, the SH 99 toll plaza at exit 48 has been converted to cashless tolling with PikePass or PlatePay as options. The rest of the turnpike (including the Spur) has been converted to PlatePay as of December 15, 2022.
Toll revenues from the Cimarron Turnpike are not necessarily used to maintain it. Under a practice known as cross-pledging, all OTA toll revenue is pledged against the sum of OTA's indebtedness, including bonds financing the state's other turnpikes.

## Services

Law enforcement along the Cimarron Turnpike is provided by Oklahoma Highway Patrol Troop YA, a special troop assigned to the turnpike.

## Future

On May 20, 2021, Senator Jim Inhofe, Republican of Oklahoma, introduced legislation to designate the portion of US-412 between I-35 in Noble County and I-49 in Springdale, Arkansas as future Interstate 42. (I-42) The bill, titled the "Future Interstate in Oklahoma and Arkansas Act" (S. 1766), was cosponsored by senators John Boozman and Tom Cotton, both Republicans of Arkansas. The senators' stated reasons for seeking an Interstate designation along the US-412 included encouraging economic development, expanding opportunities for employment in the region, making travel safer and shipping easier, attracting new businesses, and better connecting rural and urban communities. Other supporters of the measure include the mayor of Tulsa, G. T. Bynum, and the heads of both ODOT and the Arkansas Department of Transportation (ArDOT). The language of the bill was later included in the Infrastructure Investment and Jobs Act (H.R. 3684). Interstate 42 (I-42) was the proposed designation but was withdrawn. ArDOT and ODOT later resubmitted the application to the Spring 2024 meeting; AASHTO approved the route as Interstate 42, conditional on it being upgraded to Interstate standards.

## Exit list

| County | Location | mi | km | Exit | Destinations | Notes |
| Noble | ​ | 0.00 | 0.00 | | US 64 west / US 412 west – Enid | Continuation west; western end of US-412 concurrency |
| Noble | ​ | 0.00 | 0.00 | 1 | I-35 / US 64 east – Wichita, Perry, Oklahoma City | Signed as exits 1A (north) and 1B (south); exit 194A on I-35 |
| Noble | ​ | 2.7 | 4.3 | 2 | US 77 – Tonkawa, Perry | Westbound exit and eastbound entrance |
| Noble | ​ | 14.7 | 23.7 | 15 | US 177 – Ponca City, Stillwater | |
| Noble | ​ | 22.8 | 36.7 | 22 | US 64 – Morrison, Pawnee | |
| Payne | ​ | 27.7 | 44.6 | 27 | SH-312 west – Stillwater | Westbound exit and eastbound entrance; eastern terminus of SH-312 |
| Payne | ​ | 28.5 | 45.9 | 28 | SH-108 | Proposed interchange |
| Pawnee | ​ | | | — | Service Plaza | Left exits and entrances |
| Pawnee | ​ | 36.7 | 59.1 | 37 | SH-18 – Pawnee, Cushing | |
| Pawnee | ​ | 48.4 | 77.9 | 48 | SH-99 – Hallett, Jennings | |
| Pawnee | Westport | 58.6 | 94.3 | 59 | SH-48 south to US 64 – Cleveland, Mannford | Northern terminus of SH-48 |
| Pawnee | Westport | 58.6 | 94.3 | | US 64 east / US 412 east (Sand Springs Expressway) | Continuation east; eastern end of US-412 concurrency |
| 1.000 mi = 1.609 km; 1.000 km = 0.621 mi Concurrency terminus Incomplete access Unopened |||||||

## State Highway 312

State Highway 312 is an 8.5-mile long (13.7 km) spur from the Cimarron Turnpike that splits from the main turnpike at exit 27. There is one main lane toll plaza near Perkins Road that costs anywhere between $0.45 (for 2-axle vehicles with a Pikepass) to $2.50 (6-axle vehicles without a Pikepass). The spur's western terminus is at a trumpet interchange with US-177 in northern Stillwater, near Oklahoma State University. There is an incomplete access exit at Perkins Road (signed as exit 21A) and the spur starts to travel through rural areas of northern Payne County before ending at the main turnpike. The spur was built in 1981 at the cost of $4.5 million. The spur was built as a way for westbound traffic to get to Stillwater and the main campus of Oklahoma State University. Conversely, eastbound traffic uses the spur for faster access to Tulsa from Stillwater.
SH-312 originally bore no numbered designation. On August 2, 2021, the Oklahoma Transportation Commission unanimously approved a motion to apply the SH-312 designation to the turnpike. ODOT Director Tim Gatz stated in the Transportation Commission meeting that the numbering addition was primarily to aid in navigation using digital mapping and routing applications.
The entire route is in Payne County.
| Location | mi | km | Exit | Destinations | Notes |
| Stillwater | 0.00 | 0.00 | 20A | US 177 – Perkins, Ponca City | Western terminus |
| ​ | 0.7 | 1.1 | 21A | Perkins Road | Westbound exit and eastbound entrance |
| ​ | 8.5 | 13.7 | | US 412 east / Cimarron Turnpike east – Tulsa | Eastern terminus; exit 27 on US-412 / Turnpike |
| 1.000 mi = 1.609 km; 1.000 km = 0.621 mi Incomplete access ||||||