Now that really makes me think. I know many of my family members worked for the ice works in Detroit Lakes on Detroit Lake and many many tons of ice was picked up every winter. But i knew the difference between lake ice and house ice Thank God for that!! Believe our ice came in on a freight train tho i have no idea how long it keeps that way unless dry ice was used on it with saw dust. Know my grandfather and father used to get ice off St Clair lake and stored it in an old granery filed with hay bales, gunny sacks, saw dust plus one other thing but cannot remember it. But never knew what they used it for unless they froze meat!! Should have asked them tho i probably did but i forgot it and that is strange because i remember almost every thing from my youth!! Viola.