In case you all think this only applies to impossible locations like
Aspen, check out Northampton, MA, 7B2.

Read the obstacle departure procedure. Look at the obstacles
on the approach place and imagine how much margin you would
have if you departed there and followed the procedure. You
need more that 1000 feet only a few runway lengths ahead.

It's a pretty scairy ridge out there, and it's at sea level!

Bill Hale