I tend to agree with Jim. Wikipedia (always the definitive source :-) says the average power pole in the US is 40' long, set 6' in the ground, so 34' from ground to tip. I seem to recall from my railway museum days that 35' poles were common during the "interurban era" (pre WWII) set five feet in the ground for a overall height of 30'. Longer or shorter poles were always available, but only used when really needed.
