If you've got a tall tree, how about a black insulated end-fed line tossed up and over the top, feed it with an L-network tuner and a really, really good ground.
I've done that with 135 ft and it nearly disappears, plus it'll work all the way down to 80 Meter CW.
Just a thought (they're sufficiently rare for me that I try to make note of them when they wander through my mind...)
-- Handlebar --