... which is the reason you see so many altitude standards in Jeps - MOCAs, MORAs, MEAs etc. etc. and their associated annotations on the charts.
As an example: An altitude on the chart annotated with a "T" (mnemonic - you are Trusting the state's rules) means that the altitude provides terrain clearance of either: plus or minus 10 miles, or 5 miles or 12.5 degrees out to 30 miles, surrounded by a 5 mile buffer - all depending on the state you are flying in.