in SD, do employees have a right to any breaks during the day? I work at a gas-station/store by an interstate and I'm on my feet all day long - none stop. do I have a right to a morning or afternoon break? what about lunch? do I get paid during that time or does my boss have the right to withhold pay?

It appears that South Dakota does not require rest breaks or meal breaks. When I searched their DOL website for "work hours" it referred me to the federal DOL site and federal law does not require either.

However, if you are working and don't get at least a 20-minute uninterrupted meal break (for example, if you're eating lunch and a customer comes in who you must service), the entire period must be paid.