inside LA, you can find places if you try. maybe a loading dock?
i live in westchester, and we have drunk curb's, (imagine a 45 degree curb), i put 1 or 2 car ramps stacked up on the curb, then drive it diagonally, so that only 1 tire is up on the sidewalk. i can get a wheel about 3' above the curb, so thats about 4' rise. plenty for the time being =)
extended length - actual shock travel = compressed height.
for example, my foxes are 9.75 travel, unless you take out the bottom-out donut.