Park Service to Increase Entrance Fees:
Entrance fees are scheduled to rise at national parks over the next three summers, though a public outcry over some of the increases could cause the government to reconsider.
A few increases have already taken effect.
The National Park Service plans to phase in higher rates for park passes and vehicle fees at 131 of the 390 parks, monuments and other areas it manages. The government does not collect fees at the other sites in the park system.
...
Under the new fee structure, annual park passes will generally range from $10 to $40. Fees per person would range from about $5 to $12; per vehicle, they would be about $10 to $25.
A $50 fee for an annual pass has already taken effect at Grand Canyon and Zion and for a combined pass into Grand Teton and Yellowstone.
The most efficient way to deal with park congestion is to increase the access price. Let's hope the Park Service is increasing them enough.
Note: Higher user fees are less equitable, but my preference is to handle equity problems with the tax code.