The law can vary from state to state but in most states when you park your vehicle near a stop sign you must park your vehicle at least 30 feet away from any stop sign.
That 30 feet distance applies to Yield Signs and Stop Lights as well.
So if you are parked at least 30 feet away from any stop signs then you're likely legal in all states but if you park any closer than 30 feet you might get a ticket or have your vehicle towed away.
So to prevent any problems or possible tickets make sure you park your vehicle at least 30 feet away from any stop sign.