Question: Where are the headquarters of the league the Denver Pioneers play in?

full_context: Document 1: Summit League: The Summit League, or The Summit, is an NCAA Division I intercollegiate athletic conference with its membership mostly located in the Midwestern United States from Indiana and Illinois on the East of the Mississippi River to the Dakotas and Nebraska on the West, with additional members in the Western state of Colorado and the Southern state of Oklahoma. Originally dubbed the Association of Mid-Continent Universities in 1982, on June 1, 2007, the conference changed its name from the Mid-Continent Conference. League headquarters are in Elmhurst, Illinois.
Document 2: Big Ten Conference: The Big Ten Conference (B1G), formerly Western Conference and Big Nine Conference, is the oldest Division I collegiate athletic conference in the United States. Despite its name, the conference consists of 14 members (as of 2016). They compete in the NCAA Division I; its football teams compete in the Football Bowl Subdivision (FBS), formerly known as Division I-A, the highest level of NCAA competition in that sport. The conference includes the flagship public university in each of 11 states stretching from New Jersey to Nebraska, as well as two additional public land grant schools and a private university.
Document 3: 2014–15 Denver Pioneers men's basketball team: The 2014–15 Denver Pioneers men's basketball team represented the University of Denver during the 2014–15 NCAA Division I men's basketball season. The Pioneers, led by eighth year head coach Joe Scott, played their home games at Magness Arena and were members of The Summit League. They finished the season 12–18, 6–10 in Summit League play to finish in a tie for sixth place. They lost in the quarterfinals of The Summit League Tournament to North Dakota State.
Document 4: Western Athletic Conference: The Western Athletic Conference (WAC) is an American collegiate athletic conference formed on July 27, 1962 and affiliated with the National Collegiate Athletic Association (NCAA) Division I. The WAC covers a broad expanse of the western United States, with member institutions located in Arizona, California, New Mexico, Utah, and Washington, along with the "non-western" states of Missouri and Illinois (traditionally associated with the Midwest), as well as Texas (traditionally associated with the Southwest).
Document 5: Michigan Intercollegiate Athletic Association: The Michigan Intercollegiate Athletic Association (MIAA) is an athletic conference that competes in the NCAA's Division III. The nine teams in the conference are all located in the states of Michigan and Indiana. The Michigan Intercollegiate Athletic Association was established on March 24, 1888, making it the oldest college athletic conference in the United States. The current members of the MIAA include Adrian College, Albion College, Alma College, Calvin College, Hope College, Kalamazoo College, Olivet College, Saint Mary's College of Notre Dame, Indiana, and Trine University, formerly known as Tri-State University. Olivet and Albion are the only charter members remaining in the conference. Former members include such colleges as Michigan State University, previously Michigan Agricultural College, (1888–1907), Eastern Michigan University, previously Michigan State Normal College, (1892–1926), Hillsdale College (1888–1961), and Defiance College (1997–2000).
Document 6: Denver Pioneers men's basketball: The Denver Pioneers men's basketball team represents the University of Denver and competes in the NCAA Division I men's college basketball in Denver, Colorado. They are coached by second year head coach Rodney Billups and are members of the Summit League. They play their home games at Magness Arena.
Document 7: 2015–16 Denver Pioneers men's basketball team: The 2015–16 Denver Pioneers men's basketball team represented the University of Denver during the 2015–16 NCAA Division I men's basketball season. The Pioneers, led by ninth year head coach Joe Scott, played their home games at Magness Arena and were members of The Summit League. They finished the season 16–15, 7–9 in Summit League play to finish in sixth place. They defeated Nebraska–Omaha in the quarterfinals of The Summit League Tournament to advance to the semifinals where they lost to South Dakota State.
Document 8: 2016–17 Denver Pioneers men's basketball team: The 2016–17 Denver Pioneers men's basketball team represented the University of Denver during the 2016–17 NCAA Division I men's basketball season. The Pioneers, led by first-year head coach Rodney Billups, played their home games at Magness Arena and were members of The Summit League. They finished the season 16–14, 8–8 in Summit League play to finish in a three-way tie for fourth place. They lost in the quarterfinals of the Summit League Tournament to South Dakota State.
Document 9: Southeastern Conference: The Southeastern Conference (SEC) is an American college athletic conference whose member institutions are located primarily in the Southern part of the United States. Its fourteen members include the flagship public universities of ten states, three additional public land grant universities, and one private research university. The conference is headquartered in Birmingham, Alabama. The SEC participates in the National Collegiate Athletic Association (NCAA) Division I in sports competitions; for football, it is part of the Football Bowl Subdivision (FBS), formerly known as Division I-A.
Document 10: 2011–12 Denver Pioneers men's basketball team: The 2011–12 Denver Pioneers men's basketball team represented the University of Denver during the 2011–12 NCAA Division I men's basketball season. The Pioneers, led by fifth year head coach Joe Scott, played their home games at Magness Arena and were members of the West Division of the Sun Belt Conference. They finished the season 22–9, 11–5 in Sun Belt play to finish in second place in the West Division. They lost in the semifinals of the Sun Belt Basketball Tournament to WKU. Despite having 22 wins, the Pioneers did not accept an invitation to a post season tournament.
Document 11: 2015–16 Denver Pioneers women's basketball team: The 2015–16 Denver Pioneers women's basketball represent Denver University in the 2015–16 NCAA Division I women's basketball season. The Pioneers, led fourth year head by Kerry Cremeans, play their home games at the Magness Arena and are members of The Summit League.
Document 12: Missouri Valley Conference: The Missouri Valley Conference (also called MVC or simply "The Valley") is the second-oldest collegiate athletic conference in the United States. Currently, its members are located in the midwestern United States. The conference participates in the NCAA's Division I.
Document 13: Mountain West Conference: The Mountain West Conference (MW) is one of the collegiate athletic conferences affiliated with the National Collegiate Athletic Association (NCAA) Division I Football Bowl Subdivision (FBS) (formerly I-A). The MW officially began operations in July 1999. Geographically, the MW covers a broad expanse of the Western United States, with member schools located in California, Colorado, Hawaii, Idaho, Nevada, New Mexico, Utah, and Wyoming. Craig Thompson has served as Commissioner of the MW since its founding in 1999.
Document 14: 2013–14 Denver Pioneers men's basketball team: The 2013–14 Denver Pioneers men's basketball team represented the University of Denver during the 2013–14 NCAA Division I men's basketball season. The Pioneers, led by seventh year head coach Joe Scott, played their home games at Magness Arena and were first year members of The Summit League. They finished the season 16–15, 8–6 in The Summit League play to finish in fourth place. They advanced to the semifinals of The Summit League Tournament where they lost to North Dakota State.
Document 15: Big 12 Conference: The Big 12 Conference is a ten-school collegiate athletic conference headquartered in Irving, Texas. It is a member of the NCAA's Division I for all sports; its football teams compete in the Football Bowl Subdivision (FBS; formerly Division I-A), the higher of two levels of NCAA Division I football competition. Its ten members, located in Iowa, Kansas, Oklahoma, Texas, and West Virginia, include eight public and two private Christian schools. Additionally, the Big 12 has 12 affiliate members, eight for the sport of wrestling, one for women's gymnastics, and 3 for women's rowing. The Big 12 Conference is a 501(c)(3) nonprofit organization incorporated in Delaware.
ground_truth: Elmhurst, Illinois