by a flood caused by Hurricane Agnes. The George Washington Memorial Parkway was developed to ensure the easy linkage of George Washington's most visited places. Great Falls Park was a part of the Northern Virginia Parks system and was transferred to the NPS in 1966. A proposed bridge to span the falls was also considered but, due to a strong lobby to eliminate additional bridges over the Potomac and concerns over environmental impacts, the project was never undertaken. Access and amenities Direct access to the park is usually by way of Georgetown Pike (Virginia Route 193) and Old Dominion Drive. Major highways in the vicinity of the park which provide regional connections include the Capital Beltway (Interstate 495), the Dulles Toll Road (Virginia Route 267) and Leesburg Pike (Virginia Route 7). There is a $20 entrance fee per car for visitors who drive into the park. The park is open only during daylight hours. The park has several viewing platforms that provide visitors with vantage points overlooking the falls. The NPS operates a visitor center near the falls. Fifteen miles (24 km) of hiking trails traverse the park and follow a small stream known as Difficult Run. A scenic trail near the river travels upstream from a landing at the mouth of Difficult Run, climbs to the top of Mather Gorge and passes the falls, a dam, and a reservoir before ending in Fairfax County's Riverbend Park. Rock climbers frequent the cliffs in Mather Gorge above the Potomac. The park contains a large picnic area and sufficient parking for 600 vehicles. On busy weekends all the parking may fill up by early in the morning, creating delays and temporary closures lasting up to several hours. The NPS does not permit camping in the park. The falls total 76 feet (20 m) over a series of major cascades. The Great Falls are rated Class 5-6 Whitewater according to the International Scale of River Difficulty. The first kayaker to run them was Tom McEwan in 1975, but only since the early 1990s have the Falls been a popular destination for expert whitewater boaters in the DC area. Below the falls, through Mather Gorge, the river is rated class 2-3 and has been a very popular kayaking run since the 1960s. Entry into the water above the falls from the Virginia side is illegal. An average of seven drownings per year occur in