I already mentioned it above that all resorts have Engineered Actual Numbers, so am providing more examples here.
The engineering numbers are in the Master Plan engineering documents, if you really want to be precise about it. Go look up these documents and see exactly how professional engineers have studied all of the aspects of a resort, using engineering principals to arrive at real numbers. It's not like Planning a resort, stadium, or amusement area is somehow a brand new concept, they have been around for decades and Planning as a concept is centuries old, so there are best practices and industry specific terms that cover these things. Just like how if you are to construct a building, you don't just wing it by going to home depot and getting some lumber, there are centuries of knowledge on established architectural and construction practices that guide a modern project.
Typically the Master Plan is logged with governmental agencies as these are public areas for safety and use requirements, and so you can obtain them, (but not necessarily all are online)
Below quote is an example from Vail's 2018 master plan on the Engineered Limits (chap 2) which recommends Vails number to begin managing guests from the engineering standpoint is
19,900. There is much much more operational details on how they got that number and other aspects and details of capacity discussion in subsequent chapters if you're into that kind of stuff.
Later they talk about in this Plan, the CCC limit for Vail’s was determined to be approximately
23,160 guests. It also mentioned you can surge up to 25% over CCC on extreme peak days, so that would gives you an upper bound of
23160 *1.25= 28,950. When the manager decides to start pulling the capacity control levers whether at 19,900 or possibly earlier or later then prescribed, of course, comes down to exact human in charge on that special day.
THere are more ski resort for that particular forest land in that same planning site.
White River National Forest - Planning
www.fs.usda.gov
1 . CO M F O RTA B L E CA R R Y I N G CA PAC I T Y Comfortable Carrying Capacity (CCC) is defined as a level of utilization for the ski area (the number of visitors that can be comfortably accommodated at any given time) that guarantees a pleasant recreational experience, without overburdening the resort infrastructure. It is commonly referred to as “comfortable carrying capacity,” “skier carrying capacity,” “skiers at one time,” and other ski industryspecific terms. Accordingly, the design capacity does not normally indicate a maximum level of visitation, but rather the number of visitors that can be “comfortably” accommodated on a daily basis. The calculation of the CCC of a mountain is a complex issue and is an important planning tool for the resort. Related skier service facilities can be planned, including on-mountain seating, mountain restaurant requirements, sanitary facilities, parking, and other skier services with proper identification of the mountain’s true capacity. The CCC figure is based on a balance of the uphill capacity of the lift system and the downhill capacity of the trail system.
2 . MANAGE-TO PROCESS The Manage-To process allows Vail and the Forest Service to manage for health, safety and welfare considerations, and a high-quality skier experience based on calculated planning numbers (threshold). Manage-To is a flexible process developed by Vail, the Town of Vail and the Forest Service to evaluate impacts to ski area operations at Vail when skier numbers exceed 19,900, and outline steps to manage skier numbers on subsequent days if it is likely that the subsequent day’s skier numbers may exceed the Manage-To threshold.
Vail will consult with Forest Service representative at the end of any day that exceeds the threshold to evaluate health, safety and quality welfare considerations of the day’s operation. Manage-To actions may be implemented as warranted by the review of the subject day’s operational impacts. There are a variety of Manage-To actions available to Vail, which help manage skier numbers. The following list is for illustrative purposes only and does not represent an all-inclusive list or mandatory steps.
• Restrictions on employee and dependent passes
• Stop issuance of complimentary tickets
• Manage ticket pricing
• Restrict student and merchant passes
Vail will rely on evaluation of current operations and conditions, its prior experience, and best judgment to determine which Manage-To action or actions, if any, to implement for management of skier volume on subsequent days.
To the OP, here is what I could find from searching for your list of resorts.
Of course if they actually did some development from this quote, the current CCC would likely be higher than these old timestamps. The Plans often quote how the CCC will increase with improvements, but there may be other regulations or permitting that would imply other thresholds/limits. You'd have to read the chapters to really get the details and nuances.
Remember multiply by 1.25 to get the occasional peak limits.
The 2015 Snowmass Masterplan states CCC is
12360
The 2014 JacksonHole states CCC is
7690
Steamboat 2019 Plan states CCC is
13050
Telluride 2016 Plan states CCC is
6550