Lake Keechelus Iced Over

I could hardly believe it when I discovered that Lake Keechelus is still iced over.
Yesterday, April 26.
Wow!
I wonder why?
My best guess is the unusually heavy snowfall in the Cascades, which provided snow to insulate the ice from the warm air above.
Aside to out-of-staters: Lake Keechelus is a big lake (9 miles) alongside I-90 just east of Snoqualmie Pass in central Washington state. Its elevation is about 2,600 feet. It is usually iced over during the coldest portion of the winter, but this is late April!

On a related topic -- This has been one of the drier winters at my house in the last 15 years. I know, that is inconsistent with the near record heavy snowfall in the mountains.