The Forest Service manages certain Recreation Areas around the country, and they have a policy of No Disposable Containers. I don't know if they will search your bag, but I believe they will issue a fine for possession of a disposable container.

In other words, no bottles, no cans. Leave them in your car.

All wine-sipping must be done from re-usable containers. Beer is tougher. Hard liquor could still be abused; but dozens of beer cans/bottles might become a thing of the past.

A ranger issuing tickets could probably gather enough revenue to justify his presence.

For that matter, if people are accustomed to paying $4 to park at the top, such income could support a 'government presence' at the parking area. Someone to search bags -- for the common good.

It seems clear that trash and undesirables go together; so, who needs them?