Question: Berrys is an unincorporated community on a tributary of the Patomac River, that is 55.6 miles long, and has two forks that are each approximately how long?
Context: Myrtle Creek is a short tributary of the South Umpqua River in Douglas County in the U.S. state of Oregon.  Its main stem, formed by the confluence of two forks just south of the city of Myrtle Creek, is only about 1 mi long.  Its only named tributaries are the two forks, North Myrtle Creek and South Myrtle Creek, each of which is much longer than the main stem. Short Creek is an unincorporated community in Brooke County, West Virginia, US.  Approximately 1/2 mile from the Ohio River, Short Creek flow from Northern Ohio County into Brooke County.  The creek, Short Creek, has two forks, North and South Fork.  Both forks rise in the very western reaches of Washington County, and very southwestern Allegheny County, in Pennsylvania.  There are several very small settlements along the creek.  There were small family farms and coal mines along the creek. Berrys is an unincorporated community on the Shenandoah River in Clarke County, Virginia.  Berrys was originally known as Berry's Ferry for the ferry operated there.  Today, Harry Flood Byrd Bridge spans the Shenandoah at Berrys carrying U.S. Route 50 and U.S. Route 17. The Van Duzen River is a river on the north coast of California.  It is a major tributary of the Eel River and drains 429 sqmi , mostly in Humboldt County, with a small portion in Trinity County.  The river travels 63 mi from its headwaters on the west side of the North Coast Range to its confluence with the Eel River, about 14 mi upstream from the Pacific Ocean and 17 mi south of Eureka, California.  The river's elevation is over 5000 ft at its source and only 60 ft when it merges with the Eel River.  The river has two forks in its upper reaches.  The North Fork travels northwest until it reaches the small town of Dinsmore, where it starts flowing west.  The Little Van Duzen, which also flows northwest, joins the North Fork a few miles later.  The river flows roughly west from then on.  It meets its largest tributary, Yaeger Creek, about 5 mi before it reaches the Eel River. Five Forks is an unincorporated community in Gwinnett County in the U.S. state of Georgia near the intersections of River Road, Five Forks Trickum, Oak Road and Dogwood Road.  It is a former mail-stop served from the mid-1800s to early 1900s by the Yellow River Post Office and still appears on maps as a small unincorporated community between Snellville and Lawrenceville.  It is connected to another nearby mail-stop called Trickum by the unusually named Five Forks Trickum Road.  Currently, the center of Five Forks is home to some restaurants and shopping centers, as well as relatively new Ronald Reagan Park across the street from the Five Forks Library branch. St. Mary's Peninsula is part of the Western Shore region of Maryland.  From the Charles County line, just north of Charlotte Hall, Maryland, to the southern tip of St. Mary's County at Point Lookout State Park, St. Mary's Peninsula stretches about 39 mi .  It is bordered on the southwest by the Potomac River, on the north and east by the Patuxent River and on the east by Chesapeake Bay.  From the end of these two rivers, the peninsula has about 15 miles of shoreline along the Bay's western shore from Lexington Park, Maryland to Point Lookout.  Its shoreline stretches for a total of 536 miles along the Patuxent River, Patomac River and the Chesapeake Bay. The Shenandoah River is a tributary of the Potomac River, 55.6 mi long with two forks approximately 100 mi long each, in the U.S. states of Virginia and West Virginia.  The principal tributary of the Potomac, the river and its tributaries drain the central and lower Shenandoah Valley and the Page Valley in the Appalachians on the west side of the Blue Ridge Mountains, in northwestern Virginia and the Eastern Panhandle of West Virginia. Forks of Waters (formerly Strait Creek) is an unincorporated community located in Highland County, Virginia, United States.  Forks of Waters is located approximately 6 mi northeast of Monterey, Virginia at the junction of U.S. Route 220 and Virginia State Route 642.  Forks of Waters is so named due to the convergence of the Strait Creek with the South Branch Potomac River near the community.  After passing through Forks of Waters, the South Branch Potomac River enters West Virginia approximately 1 mi to the northeast. Dairy Creek is a 10.55 mi tributary of the Tualatin River in the U.S. state of Oregon.  It begins at the confluence of its east and west forks near the unincorporated community of Schefflin and meanders southeast across the Tualatin Valley to the Tualatin River near Hillsboro, in Washington County.  East Fork Dairy Creek begins at in Columbia County, slightly north of its border with Washington County, and flows generally south for 22 mi .  West Fork Dairy Creek, also about 22 mi long, forms at , near the unincorporated community of Tophill, and flows generally southeast.  Before railroads displaced river boats on the Tualatin, some steamships also worked the lower section of Dairy Creek, with plans to go as far up stream as Centerville. Shannon Creek is a short tributary to the Baker River in Whatcom County, Washington, near the southwest border of North Cascades National Park.  It rises in two forks a few miles south of Mount Shuksan; the glacier-fed north fork begins at elevation 5016 ft , and the non-glacial south fork begins at 2611 ft .  Roughly halfway through its length, the two forks join and then flow into Baker Lake reservoir, at elevation 725 ft .  Shannon Creek joins the Baker several miles downstream of Sulphide Creek and upstream of Swift Creek, a much larger south-flowing drainage.
Answer: 100 mi