Side note, but I don't see how a resort in the eastern US can survive without snowmaking, which is insanely expensive. I'm frankly surprised more small resorts haven't shuttered due simply to operational costs.
From the economic perspective of visitor numbers, it is a rare large ski resort that doesn't have green-season activities these days. The de rigueur offerings seem to be zip lines, high-ropes courses, Segway tours, and wedding venues. Those are generally one-time-use sorts of activities, though, not the sort of things that bring people in for long vacations or serial visits. I think the recent explosion of mountain bike trail networks (both DH and XC) demonstrates a recognition of the need to provide activities that will draw visitors to the region for ongoing access to outdoor recreation in the increasingly-long warmer season.
And yet, the work is still seasonal. Even an employee who works winter and summer for a resort will get laid off for six weeks in April and May so that they do not become eligible for benefits. That is a problem, too (obviously not just in the snowsports industry). I'd be curious, for example, to know how many of those 10,000 ski/snowboard jobs are ft/with benefits.