Carson Pass is not one of the Trans Sierra Passes that closes for the winter. It is more likely to close for brief periods during and after significant storms than I-80 or HWY50, but is kept open year round. For those traveling to and from the Eastern Sierra, the shortcut over Monitor Pass does close for the winter, but is generally closed for a shorter period than Ebbetts, Sonora, and Tioga Passes.
By the way, the past several years, the passes that do close generally have been closed around December-through early/mid-May. Late October-November through late May/early June closure is possible, but not the recent norm. Thanksgiving drives through these areas have been possible, and even Christmas/New Year's last year, but the latter was exceptional.
I never go up there in the colder months. Just made the usual assumption that it was like Tioga or Sonora. Should have considered it better. What with Kirkwood in the area etc.. I'm just going to copy and paste your words here and give you credit for the info on the page because it's a very good description! Hope that's ok.
I'm glad to make a small contribution to a page by someone whose work has led me into fun areas...I'd just put your caltrans link and note that HWY 88 is a year round highway with possible brief closures or chain requirements during and after heavy snowstorms due to snow and avalanche risk. If you want to include details about travel over Monitor Pass to the Eastern Sierra with general closure dates, put my caltrans link as well and/or mention checking HWY 89 (Monitor Pass). No need to credit me, but I'm fine either way.
I added a page for Black Butte. When you get a chance, could you make a link for the page like you did for the other peaks in the region. Thanks.
Thanks for adding it. It's linked. I was wondering when someone would get around to it.