The Emyn Nimbrith comprise shattered remnants of the Iron Mountains, filling the wide, north-south expanse dividing Forodwaith from Eriador. The hills were rough and rugged, marked neither by road nor trail. In summer, greenery sprouted from various cracks and crevices, and on the sunny hilltops coarse grass grew in short, scraggly patches. There was not enough vegetation to change the bleak color of the hills or to attract herd animals in any numbers, but the Emyn Nimbrith were a natural habitat for rats, mice, snow hares and the small predators that hunted them. Snow hares survived the harsh winters by making their burrows and warrens deep beneath the cracked and crumbling stone of the hills. In the warm weather months, the hills became a refuge for Angmarean spies or for bandits driven from the South. For this reason, the Lumimiehet avoided venturing very far into the hills, hunting only along their outer edges.
On clear days, the highest ridges of these hills offered several vantage points. To the northwest, the sun's sparkling reflection could be seen playing upon the Bay of Cracking Ice, while southwestwards the Wash Tundra announced its location with a shimmer of green and tiny glints of water. Turning north and east, the vast Herd Tundra disappeared into the infinity of haze and distance. To the southeast, the grim, glowering peaks of Angmar could be discerned. When conditions were right, a hint of haze at the base of the westernmost peaks of Angmar betrayed the location of Carn Dûm.
The winter snows turned the hills truly white and, at that time of year, the smaller mammals and reptiles hibernated, and predators moved south in search of food. In winter, the hills were usually devoid of Man or Orc. However, in spring it was not uncommon for Lumimies hunting parties to find the lifeless, frozen bodies of Angmarean deserters or bandits, tucked away in some sheltered hollow. Beneath the Emyn Nimbrith lay the remnants of Thaurung, a giant dragon that had perished in the War of Wrath, buried in the destruction of the Iron Mountains. The Lumimiehet called the cave Sinikäden Kuoleman Reikä, Hole of the Blue-handed Death, because of the deadly disease transmitted through the fangs of a death shrew, and regarded it as one more reason to avoid the hills..