The Orocarni roughly followed the line of the Red Mountains, which had been made by the Valar before Arda was marred and the symmetry was lost in the wars against Melkor. On the western slopes of the Orocarni grew the Wild Wood, near a great waterfall of a river that flowed into the Inland Sea of Helcar where the bay of Cuiviénen lay, where the Elves woke. Concerning Elven folk, the Dark Elves lived in the forests bordering these mountains, and likely had similar capital cities to the one of Lothlórien and the one of Mirkwood, and similar architecture, as well. At their northern edge the Orocarni connected with the Iron Mountains (Ered Engrin) resembling the Blue Mountains (Ered Luin) in the far west.
Four of the seven Fathers of the Dwarves awoke in the range. After the end of the First Age the Orocarni remained, and ran through the center of the land of Rhûn. In the Second and Third Ages, they were home to the Dwarven clans of the Ironfists, Blacklocks, Stonefoots, and Stiffbeards. The Ironfists and Stiffbeards lived in the T-shaped northern half while the Blacklocks and Stonefoots lived in the backwards-C-shaped southern half. It is not explained by Tolkien who lives in the far-north, center-north, center-south, or far-south quarters. However, the most probable theory is that the Stiffbeards lived in the far-northern Orocarni, the Ironfists lived in the center-northern Orocarni, the Stonefoots lived in the center-southern Orocarni, and the Blacklocks lived in the far-southern Orocarni.
One of the rivers that arose in the Orocarni flowed into the inland Sea of Rhûn.
Because the Orocarni were far to the east, they were not visited by the Eldar, and the Edain did not reach them until the Fourth Age. The Orocarni do not appear in any of the tales of the Red Book of Westmarch. However, it is known that the mountains were extremely rich with every kind of mineral, bursting at the seams with them..
|Mountain Ranges of Arda|
Ash Mountains | Echoriath | Ephel Dúath | Ered Gorgoroth | Blue Mountains | Ered Lómin | Grey Mountains | Ered Wethrin | Iron Hills | Iron Mountains | Misty Mountains | Mountains of Angmar | Mountains of Mirkwood | Mountains of Mithrim | Orocarni | Pelóri | Wall of the Sun | White Mountains | Yellow mountains
|Dwarven Realms of Middle-earth throughout the Ages|
|Years of the Trees & First Age:||Bar-en-Nibin-Noeg | Belegost | Khazad-dûm | Mount Gundabad | Nogrod | Nulukkizdîn | Orocarni|
|Second Age:||Khazad-dûm | Mount Gundabad|
|Third Age:||Grey Mountains | Iron Hills | Khazad-dûm | Lonely Mountain | Northern Blue Mountains|
|Fourth Age:||Glittering Caves | Khazad-dûm | Lonely Mountain|