Just this sort of possibility is why California's Prop. 21 came about.
Unfortunately I know way too much about this one....wife's deeply involved with Calif. State Parks via one of the bigger supporting Non-Profits. I'll try to do the short version.
I won't touch the right and wrongs of taxes disguised as fees but basically California's State Park System (including CSRM, etc.) have been funded from the State's General Fund. Most of the parks also survive on donations via various non-profits and volunteer labor. CSRM is very fortunate on this count.
For about the past 15-20 years the park's budget has been slowly reduced to the point where they're about to fall over a cliff. There's over a billion dollar backlog of differed basic maintenance (that includes zero fluff projects). Ranger staffing is actually skeletal...that's why you don't see them collecting entrance fees at the gates. Also, parks are one of the few State Programs that actually bring in more tax revenue to the State than is spent...something like for each $1 the return is about $2.50. It would be a hell of a lot higher if they had been smart on the park vendor contracts...they've known it for years, and are working on it as contracts go up for renewal. They also know that most people don't voluntarily pay at the self pay parks. The Legislature took away Ranger funding years ago so Parks can't do a thing about it.
Arnold's saving of the system last year was pure B-S. The minimal operations plan he took credit for was already worked out by parks management, he used it as an excuse to play hero (actually he did it two years running, it's just that the first time the people forced him to keep the parks budgeted).
Closing the parks will be a tourist draw disaster to the State economy, it'll cost nearly $100 million in penalties (broken contracts with vendors), nobody knows how much it will cost to reopen closed parks (I asked the operations guys in Sacramento) If the basics like dirt parking lots, roads, trails, septic systems, power lines, and roofs need fixing.... There's also the State's liability for forest fires that start in Parks, pot plantations, homeless camps, trespasser's injuries, etc.
Anyway, Prop. 21 is a last ditch effort to get the Park System out of the General Fund. The money raised will be a dedicated fund for the State Park System and a select few related land uses. The bill language makes it tough to impossible for politicians to steal the funds for elsewhere. The money expected will just keep all the parks open and staffed but won't address the maintenance backlog, new projects, new acquisitions, nothing.
If you live in SoCal, that $18 is like a day's parking/entrance fee at a State Beach. Prop. 21's $18 fee on the car registration will be an annual pass to almost all State Parks except for several that require outside vendor support like Parking Garages, ferry service.
Basically visit one or two State Parks after it passes and you get your money back for the year.
HDS Decals and other amusing projects