Question: Where does the Merrimack River start in the state where Washington University in the city that hosted the 1904 Summer Olympics is located?

full_context: Document 1: Louis Wilkins: He competed for the United States in the 1904 Summer Olympics held in St Louis, United States in the pole vault where he won the bronze medal.
Document 2: 1904 Summer Olympics: The 1904 Summer Olympics, officially known as the Games of the III Olympiad, was an international multi-sport event which was celebrated in St. Louis, Missouri, in the United States from August 29 until September 3, 1904, as part of an extended sports program lasting from July 1 to November 23, 1904, at what is now known as Francis Field on the campus of Washington University in St. Louis. It was the first time that the Olympic Games were held outside Europe.
Document 3: Howard Valentine: He competed for the United States in the 1904 Summer Olympics held in St Louis, United States in the 800 metres where he won the silver medal and in the 1500 metres event where he finished seventh. He also competed for the New York Athletic Club team in the 4 mile team race against Chicago AA with teammates Arthur Newton, George Underwood, Paul Pilgrim and David Munson. They won the race and the gold medal.
Document 4: Washington University in St. Louis: Graduate schools include the School of Medicine, currently ranked sixth in the nation, and the George Warren Brown School of Social Work, currently ranked first. The program in occupational therapy at Washington University currently occupies the first spot for the 2016 U.S. News & World Report rankings, and the program in physical therapy is ranked first as well. For the 2015 edition, the School of Law is ranked 18th and the Olin Business School is ranked 19th. Additionally, the Graduate School of Architecture and Urban Design was ranked ninth in the nation by the journal DesignIntelligence in its 2013 edition of "America's Best Architecture & Design Schools."
Document 5: 400 metres at the Olympics: Only two athletes have won the event twice: Marie - José Pérec became the first to defend the title in 1996, then Michael Johnson followed with victories in 1996 and 2000. No athlete has won more than three medals. Several medalists in the event have also had success in the 200 metres at the Olympics: Johnson, Perec, Szewińska and Valerie Brisco - Hooks have all won titles at both distances. Athletes chosen for the event almost always form part of their nation's team for the 4 × 400 metres relay at the Olympics.
Document 6: Washington University in St. Louis: The Washington University School of Medicine, founded in 1891, is highly regarded as one of the world's leading centers for medical research and training. The School ranks first in the nation in student selectivity. Among its many recent initiatives, The Genome Center at Washington University (directed by Richard K. Wilson) played a leading role in the Human Genome Project, having contributed 25% of the finished sequence. The School pioneered bedside teaching and led in the transformation of empirical knowledge into scientific medicine. The medical school partners with St. Louis Children's Hospital and Barnes-Jewish Hospital (part of BJC HealthCare), where all physicians are members of the school's faculty.
Document 7: Mississippi River: The Mississippi River is the chief river of the second - largest drainage system on the North American continent, second only to the Hudson Bay drainage system. Flowing entirely in the United States (although its drainage basin reaches into Canada), it rises in northern Minnesota and meanders slowly southwards for 2,320 miles (3,730 km) to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains all or parts of 31 U.S. states and 2 Canadian provinces between the Rocky and Appalachian Mountains. The Mississippi ranks as the fourth - longest and fifteenth - largest river in the world by discharge. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana.
Document 8: Mississippi River: The Mississippi River is the chief river of the second - largest drainage system on the North American continent, second only to the Hudson Bay drainage system. The stream is entirely within the United States (although its drainage basin reaches into Canada), its source is Lake Itasca in northern Minnesota and it flows generally south for 2,320 miles (3,730 km) to the Mississippi River Delta in the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains all or parts of 31 U.S. states and two Canadian provinces between the Rocky and Appalachian Mountains. The Mississippi ranks as the fourth - longest and fifteenth - largest river in the world by discharge. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana.
Document 9: Washington University in St. Louis: Washington University in St. Louis (WashU, or WUSTL) is a private research university in St. Louis, Missouri. Founded in 1853, and named after George Washington, the university has students and faculty from all 50 U.S. states and more than 120 countries. As of 2017, 24 Nobel laureates in economics, physiology and medicine, chemistry, and physics have been affiliated with Washington University, nine having done the major part of their pioneering research at the university.Washington University is made up of seven graduate and undergraduate schools that encompass a broad range of academic fields. To prevent confusion over its location, the Board of Trustees added the phrase "in St. Louis" in 1976.
Document 10: Meramec River: The Meramec River (/ ˈmɛrɪmæk /) is one of the longest free - flowing waterways in Missouri, draining 3,980 square miles (10,300 km) while wandering 218 miles (351 km) from headwaters near Salem to where it empties into the Mississippi River near St. Louis at Arnold and Oakville. The Meramec watershed covers six Missouri Ozark Highland counties -- Dent, Phelps, Crawford, Franklin, Jefferson, and St. Louis -- and portions of eight others -- Maries, Gasconade, Iron, Washington, Reynolds, St. Francois, Ste. Genevieve, and Texas. Between its source and its mouth, it falls 1,025 feet (312 m). Year - round navigability begins above Maramec Spring, just south of St. James. The Meramec's size increases at the confluence of the Dry Fork, and its navigability continues until the river enters the Mississippi at Arnold, Missouri.
Document 11: Washington University in St. Louis: In 1867, the university opened the first private nonsectarian law school west of the Mississippi River. By 1882, Washington University had expanded to numerous departments, which were housed in various buildings across St. Louis. Medical classes were first held at Washington University in 1891 after the St. Louis Medical College decided to affiliate with the University, establishing the School of Medicine. During the 1890s, Robert Sommers Brookings, the president of the Board of Trustees, undertook the tasks of reorganizing the university's finances, putting them onto a sound foundation, and buying land for a new campus.
Document 12: Missouri River: The Missouri River is the longest river in North America. Rising in the Rocky Mountains of western Montana, the Missouri flows east and south for 2,341 miles (3,767 km) before entering the Mississippi River north of St. Louis, Missouri. The river takes drainage from a sparsely populated, semi-arid watershed of more than half a million square miles (1,300,000 km), which includes parts of ten U.S. states and two Canadian provinces. When combined with the lower Mississippi River, it forms the world's fourth longest river system.
Document 13: Alan Valentine: Alan Chester Valentine (February 23, 1901 – July 14, 1980) was an American academic who competed on the gold-medal winning American rugby union team in the 1924 Summer Olympics, was president of the University of Rochester, and served in the Truman Administration as a Marshall Plan official and as the first head of the Economic Stabilization Agency.
Document 14: Washington University in St. Louis: Washington University in St. Louis (Wash. U., or WUSTL) is a private research university located in St. Louis, Missouri, United States. Founded in 1853, and named after George Washington, the university has students and faculty from all 50 U.S. states and more than 120 countries. Twenty-five Nobel laureates have been affiliated with Washington University, nine having done the major part of their pioneering research at the university. Washington University's undergraduate program is ranked 15th by U.S. News and World Report. The university is ranked 32nd in the world by the Academic Ranking of World Universities.
Document 15: Lake of the Ozarks: The Lake of the Ozarks is a large reservoir created by impounding the Osage River in the northern part of the Ozarks in central Missouri. Extents of three smaller tributaries to the Osage are included in the impoundment: the Niangua River, Grandglaize Creek, and Gravois Creek. The lake has a surface area of 54,000 acres (220 km) and 1,150 miles (1,850 km) of shoreline, and the main channel of the Osage Arm stretches 92 miles (148 km) from end to end. The total drainage area is over 14,000 square miles (36,000 km). The lake's serpentine shape has earned it the nickname ``The Magic Dragon '', which has in turn inspired the names of local institutions such as The Magic Dragon Street Meet.
ground_truth: near Salem
sub_queries: Athletics at the 1904 Summer Olympics >> located in the administrative territorial entity Answer: St Louis
Where is Washington University in St Louis located? Answer: Missouri
where does the merrimack river start in Missouri Answer: near Salem