Mike,
Not sure if the Swiss chase fines with collection agencies in the USA; so if you never go back to Switzerland, you may be lucky. But if you come back to Switzerland you might not be so lucky.
The Swiss add non-payment fees to fines and bills which are not paid on time. If you fly in, the might spot it at the airport (if you cross a land border no checks). But, worst case, if you are driving, the police do a spot check and find your record, it would be immediate driving ban (hire car towed away, you left at side of road), and a lot more expensive than a mere 250 Franks.
But do you want a conviction listed against your name, even if it is in a foreign country?
PS It is "CHF 250", '$' is the symbol for dollars, not Francs.
PPS, try typing the text into an online translator (don't make any typos), usually they are approximately correct, but sometimes spectacularly wrong.