The National Park Service wants to start charging entrance fees for the first time along the entire length of the nearly 185-mile Chesapeake and Ohio Canal National Historical Park starting May 1.



The agency said Monday the fees are critical to the park's operation.



It currently collects entrance fees only at the Great Falls Tavern in Potomac. The vehicle fee is $5 for a three-day pass.



That would change to $15 for a seven-day pass from the District of Columbia to Seneca Creek, 22 miles upstream. Visitors further west would pay $5 for a seven-day vehicle pass, rising to $15 in 2017.



The agency is also proposing fees for people entering the park on foot, bicycle or motorcycle, and for hiker-biker campsites.



A public comment period ends Feb. 22.