Question: What is the length of the River which has Wild Horse Creek as a tributary ?

full_context: Document 1: Dryhead Country: Dryhead Country is a region in Carbon County and Big Horn County in southern Montana between Bighorn Canyon and the Pryor Mountains. The locale was named after the piles of dry bison skulls that accumulated at the base of a local buffalo jump. The Dryhead region starts near the Wyoming border in Bighorn Canyon National Recreation Area and extends northward into the Crow Indian Reservation. Dryhead Creek drains a portion of the area, falling eastwards into Bighorn Canyon. The semi-arid basin is one of the most remote areas in Montana. The area is sparsely populated with isolated ranches.
Document 2: Horse Creek, Wyoming: Horse Creek is an unincorporated community in western Laramie County, Wyoming, United States. It lies between Horse Creek to the north, and the South Fork of Horse Creek to the south, along WYO 211 northwest of the city of Cheyenne, the county seat of Laramie County. Its elevation is 6,506 feet (1,983 m). Although Horse Creek is unincorporated, it has a post office, with the ZIP code of 82061. As of the 2010 census, Horse Creek had an estimated population of 39.
Document 3: Powder River Station-Powder River Crossing: The Powder River Crossing, officially known as Powder River Station-Powder River Crossing (48JO134 and 48JO801), is an abandoned settlement located on the east bank of the Powder River in southeast Johnson County about twenty-four miles east of Kaycee, Wyoming. It developed after a wooden toll bridge was built across the Powder River in 1877, at a site that was originally used as a ford. With crossing secured, a settlement developed here in the late 19th century, incorporating a stage stop on the Bozeman Trail. The site is notable for having well-preserved wagon ruts from the pioneer era.
Document 4: Wild Horse, Colorado: Wild Horse is an unincorporated village in Cheyenne County, Colorado, United States. The community takes its name from Wild Horse Creek, and began in 1869 as a cavalry outpost, which soon became a railway station and had expanded to a town by the mid-1870s. After a peak of population and business activities in the early 1900s, the town began dwindling by 1917, when most of it burned down in a great fire. The town rebuilt, but never at the population or business-service centralization level of its earlier years, and by the 1930s, had begun to dwindle further.
Document 5: Bighorn Mountains: The Bighorn Mountains (Apsáalookěi: "Basawaxaawúua " or "Iisaxpúatahchee Isawaxaawúua ") are a mountain range in northern Wyoming and southern Montana in the United States, forming a northwest-trending spur from the Rocky Mountains extending approximately 200 miles (320 km) northward on the Great Plains. They are separated from the Absaroka Range, which lie on the main branch of the Rockies in western Wyoming, by the Bighorn Basin.
Document 6: Wild Horse River: The Wild Horse River, formerly known as Wild Horse Creek, is a tributary of the Kootenay River, joining it near the town of Fort Steele, British Columbia, Canada. The river's canyon was the setting for the Wild Horse Creek Gold Rush and associated "war" during the gold rush of the mid-1860s.
Document 7: Yellowstone River: The Yellowstone River is a tributary of the Missouri River, approximately 692 mi long, in the western United States. Considered the principal tributary of the upper Missouri, the river and its tributaries drain a wide area stretching from the Rocky Mountains in the vicinity of the Yellowstone National Park across the mountains and high plains of southern Montana and northern Wyoming.
Document 8: Powder River (Wyoming and Montana): Powder River is a tributary of the Yellowstone River, approximately 375 mi long in northeastern Wyoming and southeastern Montana in the United States. It drains an area historically known as the Powder River Country on the high plains east of the Bighorn Mountains.
Document 9: Horse Creek (McKenzie River): Horse Creek is a tributary of the McKenzie River in near the unincorporated community of McKenzie Bridge in Lane County in the U.S. state of Oregon. It begins in the Cascade Range in the Three Sisters Wilderness of the Willamette National Forest. Its headwaters are near the Deschutes County border and the Pacific Crest Trail. It flows generally northwest to meet the river about 65 mi upstream of the McKenzie's confluence with the Willamette River.
Document 10: Wild Horse Adult Resort &amp; Spa: The Wild Horse Adult Resort and Spa was an adult entertainment complex about 14 mi east of Reno, Nevada, USA that is home to two separate legal, licensed brothels: the Wild Horse Ranch and the Mustang Ranch. The property is located in a secluded portion of the Patrick Business Park, in the far northern portion of Storey County, at 1000 Wild Horse Canyon Drive, Sparks, NV 89434. Primary access to the area is via exit 28 off Interstate 80. The nearby settlement of Patrick, from which the Business Park takes its name (and occupants their mailing addresses), is actually found across the Truckee River and thus is located in Washoe County.
Document 11: Bighorn Canyon National Recreation Area: Bighorn Canyon National Recreation Area is a national park unit established by an act of Congress on October 15, 1966, following the construction of the Yellowtail Dam by the Bureau of Reclamation. It straddles the border between Wyoming and Montana. The dam, named after the famous Crow leader Robert Yellowtail, harnesses the waters of the Bighorn River by turning that variable watercourse into Bighorn Lake. The lake extends 71 mi through Wyoming and Montana, 55 mi of which lie within the national recreation area. About one third of the park unit is located on the Crow Indian Reservation. Nearly one-quarter of the Pryor Mountains Wild Horse Range lies within the Bighorn Canyon National Recreation Area.
Document 12: Pryor Mountains Wild Horse Range: The Pryor Mountains Wild Horse Range is a refuge for a historically significant herd of free-roaming Mustangs, feral horses colloquially called "wild horses", located in the Pryor Mountains of Montana and Wyoming in the United States. The range has an area of 39650 acre and was established in 1968 along the Montana–Wyoming border as the first protected refuge dedicated exclusively for Mustangs. It was the second feral horse refuge in the United States. About a quarter of the refuge lies within the Bighorn Canyon National Recreation Area. A group of federal agencies, led by the Bureau of Land Management, administers the range.
Document 13: Tongue River (Montana): The Tongue River is a tributary of the Yellowstone River, approximately 265 mi (426 km) long, in the U.S. states of Wyoming and Montana. The Tongue rises in Wyoming in the Big Horn Mountains, flows through northern Wyoming and southeastern Montana and empties into the Yellowstone River at Miles City, Montana. Most of the course of the river is through the beautiful and varied landscapes of eastern Montana, including the Tongue River Canyon, the Tongue River breaks, the pine hills of southern Montana, and the buttes and grasslands that were formerly the home of vast migratory herds of American bison. The Tongue River watershed encompasses parts of the Cheyenne and Crow Reservations. The Headwaters lie on the Big Horn National Forest, and the watershed encompasses the Ashland Ranger District of the Custer National Forest.
Document 14: Wild Horse Creek (Wyoming): Wild Horse Creek is a tributary of the Powder River in Wyoming. The USGS has a station on the creek, near Arvada.
Document 15: Crow Creek (South Platte River): Crow Creek is a 153 mi waterway of southeastern Wyoming and northern Colorado. Crow Creek is formed by the merger of the South Fork of Crow Creek with the Middle fork of Crow Creek, with the quick addition of the North Fork of Crow Creek about 1.5 mi downstream. All the major tributaries of Crow Creek begin in the Laramie Range and flow eastward. The headwaters of the North Fork are dammed to form North Crow reservoir, which supplies the city of Cheyenne. The middle fork is also dammed forming Granite and Crystal reservoirs, also supplying water for Cheyenne. The South Fork is the only unobstructed section and flows most of the year but not all the way to Cheyenne. Other tributaries of Crow Creek below the reservoirs are Sand Creek, Spring Creek and Brush Creek, none of which flow year round. Crow Creek continues in an eastward direction passing through the city of Cheyenne, and then heads east and south into Colorado where it eventually meets the South Platte River.
ground_truth: 375 mi long