I checked the Elder Scrolls Wiki page and it said that Elder Dragons appear after you hit level 23. I am level 27 at the moment but i have not seen a single one. Is there a certain place where i can encounter it? like the blood dragon that near rorikstead
I didn't see my first till 35ish, didn't kill my first till 38 or 39 due to the bug where they won't engage. In the 20-30 range from what i've seen is predominantly blood and frost dragons.
elder dragons are really rare and in certain specific locations after main quest. they become more common after lvl 40. ancient dragons are the same way but lvl 50.