I'll get some bullet points here.
In contact with the Western Slope No Fee coalition, they say:
..the act of designating hiking in a Wilderness as a "Specialized" use. That has not yet been adjudicated but it is ripe for it..
From the text Kathy kindly linked to that was congressional discussion the sec of interior says:
SPECIAL RECREATION PERMITS
REA authorizes the Secretary to issue a special recreation permit and charge a fee in connection with the issuance of a permit for specialized recreation uses of Federal lands, such as group activities, recreation events, and motor vehicle use. The Forest Service issues special use permits under this authority for short-term commercial recreation uses, such as outfitting and guiding, and recreation events. The permit fee revenue collected and expended on the ground will be of great benefit to recreation visitors as well as to the permit holder. Facilities used by commercial outfitters such as trails and trailheads will be better maintained which will improve the ability of permit holders to provide high quality recreation services to the public.
This authority is also used to issue special recreation permits to individuals for activities such as, white water river trips, off- highway vehicle (OHV) use and, in a limited number of cases, wilderness use. These permits are issued when we provide additional services beyond normal operation and maintenance, including constructing and maintaining specialized trails for OHVs and providing wilderness experiences in areas that receive high use.
We currently require a wilderness permit and permit fee for 8 of our 406 Congressionally designated wilderness areas that are within the National Forest System. These 8 areas had a permit prior to the enactment of REA that was authorized under the LWCFA. They include areas such as the Boundary Waters Canoe Area Wilderness on the Superior National Forest in Minnesota and the Desolation Wilderness Area on the Eldorado National Forest in California. Each of these areas has special circumstances such as an allocated visitor use system, reserved and designated campsites, and, in a few areas, an aerial sewage removal program that entail costs beyond those incurred in our normal wilderness management program.
We are developing criteria to guide to our field managers in determining when such a fee is appropriate. We do not anticipate a large number of additional fee areas. We have no intention to use the fee authority as a tool to reduce recreation visitor use. Any decision to implement a permit system to allocate use in wilderness areas to meet management objectives will be made through our land use management planning process and associated recreation capacity analysis.
So they have not used the permit system to reduce recreation visitor use directly, they've (Deschutes and Willamette) 'properly' couched it in their land use management planning and recreation capacity analysis. As a non-scientist without the funds, I don't even know on what grounds one would provide competing research or how to challenge the findings from the FS, they're almost uniquely tailored that any results of increased use can more or less fit their land management planning/forest plan etc.
I would immediately say that the CCWSP contradicts the idea of 'a large number of additional fee areas'.. we've got 79 actually in just 2 wildernesses alone.
I guess I'd attack this best stating that it is only allowed under limited use in areas that have seen high use.. You think Breitenbush Lake by the PCT gets high use? Woodpecker TH? please. The 'anticipating for the future' or overflow from people who can't go to where they want to due to permits, is really outside the scope of what a specialized permit is for.