Bridge Over Troubled Water

I'm still on my procedural mountains.
I've somewhat finalized the procedural side of the thing, but now I'm working on the graphical side. The problem is that in the end I have to resort to tiles, and these tiles should blend. I did prepare a version of the tiles which had lots of small details, but this made blending more difficult, so I'll resort to a much simpler look.
What I'd like to achieve is a realistic sequence of valleys and mountain ranges.