The last 10 hours or so I explored the Reach and mostly stayed into its borders. In all that time I was never attacked by a random dragon.

I fought one in it's lair and encountered another sitting on the field when entering the more flat region in the east, leading towards Whiterun. But that was probably the one mentioned by the scorched farmers in the Old Hroldan Inn.

I just wanted to ask if this is supposed to be. I think it is, because looking at the topography of the Reach there is hardly any room for a legit dragon fight. A defeated dragon could easily fall into the wild river and never be seen again, let alone reached by the player in order to loot it.

Or...it's a bug. I just hope it's not.

A random dragon attacked me near Markarth once (and promptly took down a quest giver), so it's possible to have a random dragon in the Reach

Besides, a random dragon may not want to fight you at all, so there's that

Mhm...thanks. Now I'm still not shure whether it works okay or not. ^^

i normal get attacked if you return to the same place you fight the first dragon just outside whiterun by the tower thing

And I never again got attacked there, but in other places while I was roaming the area outside of Whiterun at the beginning of the game.

Well, I guess we can "conclude": It's totally different for everyone. Or...random. What a surprise.