Entrance Fees and National Park Attendance

The other day a colleague, Owen Hoffman, shared his thoughts on how entrance fees might be affecting visitation at national parks.
It was a well-written piece that examined three Eastern park units -- Shenandoah, the Blue Ridge Parkway, and Great Smoky Mountains -- and Owen's personal experiences at each. In the article he noted the relative scant visitation at Shenandoah, which just happens to be the only one of the three that charges an entrance fee.
Well, a little deeper research shows an even stronger correlation between entrance fees and dampened visitation. If you compare visitation between 1997 and 2006, Great Smokies traffic was down 6.8 percent, Blue Ridge Parkway was up 3.1 percent, Shenandoah was DOWN 32.2 percent.
Anyone see a pattern?
Others are focusing more on exposing this pattern.
Check out this story in the San Jose Mercury News. Under the headline, "National Park Entry Fees Heading for Steep Hike," Paul Rogers writes that, The Bush administration is quietly moving forward with plans to hike entrance fees at 135 national parks - from Yosemite to the Everglades - in the most sweeping proposed fee increase in the history of the 91-year-old National Park Service.
And that's just the lead. Down in the body of the story Mr. Rogers notes that, In the decade before the first fee increase at Yosemite, attendance rose from 2.98 million in 1986 to 4.19 million in 1996 - a 41 percent increase. After the higher fee went into effect, attendance fell 20 percent to 3.36 million in 2006. Similarly, a 2001 report by the U.S. Department of Interior found that at 100 parks where fees were increased in 1997, attendance fell 1.5 percent. At the parks where fees weren't increased, attendance rose 11.3 percent.
How many more years of declines are necessary before Park Service officials and those members of Congress who question whether the parks are recreationally relevant in the 21st century make the connection?