[Does so]

Perhaps some 33 people backpacked in about 100 pounds of garbage each; that would be possible, though I have no idea why they’d do such a thing.

They'd probably brought in portable/wheeled coolers that could be recycled or re-used again and again. (But abandoned after intoxication set in).

[HartleyMBaldwin]

Also possible, but I’d hesitate to use the word “probably” without a bit more evidence that that is what happened.