Apologies to Mr. Gabriel.

I'm installing a 4X4X16 pole for a clothesline. I'm down to about 3 feet and I
hit solid rock. Not 'a' rock - just rock. I'll be using 10" sonotube (I have 4'
of it) and concrete.

Any rules of thumb for how deep I *should* be for good lateral stability? I can
obviously cut the pole shorter, but I'd like to have 10'-12' above ground to be
somewhat level with the mounting point on the house.

a