I have a method almost like tuttle's, except I make the path on the original terrain (slightly lower) and then make the second terrain for the path by cropping off anything besides the path. That way I can have a slight embankment/curb on the side of the path. As for adjusting height, you can do it the numeric way - or do it manually by holding the alt-key and using the move object tool. Holding the alt with it allows you to move just a smidgen rather than the bigger default increments.

---

Barbequed Pixels?

Your friendly neighborhood Wings3D nut.
Also feel free to browse my freebies at ShareCG.
There might be something worth downloading.