How long do emplyers have to keep timecards on file?¿

These posts are beginning to sound suspiciously like homework assignments to me, and we don't do homework.

If this is not the case, please explain the situation that is triggering these questions so that we can answer entirely, instead of little piece by little piece.

Unless Michigan has a longer retention requirement (and I don't think so), the FLSA requires such records be kept for at least 3 years from the "last date of entry", which for time cards, means 3 years following when the time was worked.
http://www.dol.gov/esa/regs/compliance/whd/whdfs21.htm

This isn't homework, I'm a recently promoted assistant manager and for about the last three years my employer has had us clocking out for smoke breaks and I want to know if they had to keep my timecards along with all employee timecards to see if they would give us all back pay for all the breaks under twenty minutes that we have all taken.

Also I realize michigan is an at will state Is this something me or any other employee could be fired for about asking about it or demanding the back pay?

For asking the company about internally? Theoretically, yes. For filing a claim for unpaid wages? No; that would be a violation of public policy for which a wrongful termination suit would be a distinct possibility.

If you file a claim and the employer does not have the records to back up what they did (or what they did was not legal), they'll most likely lose and have to pay up.

I take it there is not an HR Dept. in some corporate structure that you can go to for these issues?

Thanks for the reply, I feel a little safer now knowing that I should still have a job after this

There now, wasn't that easier? :)

For what it's worth, having you clock out for smoke breaks (or any other kind of break) is not, in and of itself, illegal. In fact, that can be a good way of controlling excessive breaks on the part of some employees.

What would be illegal would be in failing to add that time back in when making out your paychecks.