A plan to bump entrance fees at the 17 busiest national parks to $70 from $30 during the peak summer months will help parks struggling to cover the tab for long-delayed upkeep as crowds continue to surge. But if that peak-season pricing plan is deployed next summer, the anticipated spike in demand for $80 America the Beautiful annual passes — a mere $10 extra for a year’s access to about 2,000 federal recreation sites — could hinder the National Park Service’s quest to balance cost-sharing between visitors and the federal government. “It is unknown how these proposed increases will impact the parks and the people who visit them, but it does seem reasonable that people will see the bargain in buying the America the Beautiful annual pass for entry into all our national parks and other federal lands,” said Emily Douce, the director of budget and appropriations for the National Parks Conservation Association.