Question: Chisholm Trail Casino is a casino that opened in Duncan, Oklahoma in October of which year, the casino is 70 miles south of Norman, a city in the U.S. state of Oklahoma 20 mi south of downtown Oklahoma City?
Context: Gold Mountain Casino is a Native American casino in Ardmore, Oklahoma, owned and operated by the Chickasaw Nation.  Originally opened in 2002 as Ardmore Gaming, the facility has grown steadily and today features more than 300 gaming machines.  The casino is open 24 hours a day, seven days a week.  The 8620 sqft casino is located on the corner of P Street N.E. and Sam Noble Parkway, and can be accessed via Interstate 35, exit 33.  It is a short distance from the Ardmore Convention Center and the Hardy Murphy Coliseum.  Gold Mountain is about 34 miles north of WinStar World Casino in Thackerville, Oklahoma, and 77 miles south of Riverwind Casino in Norman, Oklahoma, which are also Chickasaw-owned gaming facilities. The Oklahoma City Streetcar (OKC Streetcar), also known as the MAPS 3 streetcar, is a streetcar system currently under-construction in Oklahoma City, Oklahoma, United States.  The 6.9 mi system will serve the greater downtown Oklahoma City area consisting of modern, low-floor streetcars.  The initial system would see two lines that will connect Oklahoma City's Central Business District with the entertainment district, Bricktown, and the Midtown District.  Expansion to other districts surrounding downtown as well as more routes in the CBD is already underway. Norman is a city in the U.S. state of Oklahoma 20 mi south of downtown Oklahoma City in its metropolitan area.  The population was 110,925 at the 2010 census.  Norman's estimated population of 120,284 in 2015 makes it the third-largest city in Oklahoma, and the city serves as the county seat of Cleveland County. Chesapeake Energy Arena, originally known as the Ford Center from 2002 to 2010 and Oklahoma City Arena until 2011, is an arena located in downtown Oklahoma City, Oklahoma, United States.  It opened in 2002 and since 2008 has served as the home venue of the Oklahoma City Thunder of the National Basketball Association (NBA).  Previously, Chesapeake Energy Arena was home to the Oklahoma City Blazers of the Central Hockey League (CHL) from 2002 until the team folded in July 2009, and the Oklahoma City Yard Dawgz of AF2 from 2004 to 2009 when the team moved to the Cox Convention Center.  In addition to its use as a sports venue, Chesapeake Energy Arena hosts concerts, family and social events, conventions, ice shows, and civic events.  The arena is owned by the city and operated by the SMG property management company and has 18,203 seats in the basketball configuration, 15,152 for hockey, and can seat up to 16,591 for concerts. Chisholm Trail Academy (CTA) is a Seventh-day Adventist co-educational high school located at Fourth and Old Betsy in Keene, Texas.  Keene is located midway between Alvarado and Cleburne, 25 mi south of Fort Worth.  Chisholm Trail Academy is situated on 27 acre of land. Chisholm Spring was a small trading post in Oklahoma Territory, two miles east of present-day Asher, Oklahoma.  The post was established by frontier cattleman Jesse Chisholm (for whom the famous Chisholm Trail was named ) in 1847.  The settlement attracted many plains Indians, but efforts to create a town were aborted when Chisholm moved to Kansas in 1862. Downtown Oklahoma City is located at the geographic center of the Oklahoma City metropolitan area and contains the principal, central business district of the region.  The CBD has over 51,000 workers and over 12000000 sqft of leasable office space to-date.  Downtown Oklahoma City is the legal, financial, economic, nightlife, and entertainment center of the region. Oklahoma City University School of Law, also known as OCU Law, is one of the professional graduate schools of Oklahoma City University.  OCU Law is located in Oklahoma City, Oklahoma and was founded in 1907.  OCU Law was located in the Sarkeys Law Center on the southwest side of the Oklahoma City University campus until Spring 2015, when it moved to a new campus near downtown Oklahoma City. The Oklahoma City Crosstown Expressway, aka I-40 Crosstown, is a roughly 5 mi stretch of Interstate 40 (I-40) just south of Downtown Oklahoma City, running along the Oklahoma River between Agnew Avenue and the I-40/I-35/I-235 "Crossroads of America" junction.  Prior to 2012, the I-40 Crosstown was an elevated stretch that bisected downtown.  The Oklahoma City Crosstown is the defacto east–west artery through Oklahoma City, serving as an unofficial dividing line between north and south Oklahoma City (the official dividing line for address purposes is Sheridan Avenue).  It is owned and maintained by the Oklahoma Department of Transportation (ODOT). Chisholm Trail Casino is a casino that opened in Duncan, Oklahoma in October, 2004.  The 22,000 sqft casino is owned and operated by the Chickasaw Nation and is open 24 hours daily.  Located along the site of the historic Chisholm Trail cattle drive, the casino is five miles north of downtown Duncan on Highway 81, south of Highway 7.  Chisholm Trail is owned and operated by the Chickasaw Nation.  The casino is 70 miles south of Norman, Oklahoma, and the Nation’s sister gaming facility, Riverwind Casino.  Chisholm Trail is 100 miles northwest of WinStar World Casino, another Chickasaw Nation gaming center, located in Thackerville, Oklahoma.
Answer: 2004