[Zuriel]

3,000 dairy cows owned by one farmer in 1300 AD? He would have needed at least 200 farmhands. And farmers with 100? Add that to those that just a cow or two, and it sounds like there must have been a half million people living in Greenland back then.

[Vigilanteman]

You need not take my word for it as it is well documented in the book Collapse: How Societies Choose to Fail or Succeed by Jared Diamond.

Greenland ruins are quite well preserved because there was almost no wood to build anything, just lots of rocks and stonework.

Does he know all 3,000 dairy cows were owned by one guy? Probably not as it was more likely a communal barn. Dairy production was central to the economy. So central, in fact, that they didn't survive a cooling climate.