Over the years there have been more than a few units of the National Park System that have been head-scratchers. Why were they added? What redeeming value did they bring to the park system?  James Ridenour who was director of the National Park Service from 1989 through 1993, was well familiar with these units. As he once put it, “I’m in complete agreement that the National Park Service has units that are unworthy of National Park Service status. That was my motive for coining the term ‘thinning of the blood’.” Members of Congress trade votes to get their local favorite on the NPS teat, usually to attract tourists. Then they don’t add money to the budget to run these units. So you have two things - you thin the quality of the system, and you thin the ability of the National Park Service to run the system. We’re going to explore some of these units, at least some of the ones that were pushed out of the National Park System, with none-other than Traveler Professor Emeritus Dr. Robert Janiskee. Bob was the one who quite some years ago started the “Pruning the Parks” series on the Traveler, and we’ve momentarily  pried him out of his retirement to discuss some of these parks with us.