And in the middle land there were the Mountains of the Wind, for a wind blew strongly there coming from the East before the Sun...
–The shaping of Middle-earth, The Ambarkanta
The Mountains of the Wind are an ancient mountain range located in southeast Rhûn. They are connected to the Rhûn forest and to the Last Desert through their foothills. They are composed of stone and clay. These mountains were named for the strong winds that blew through them from the east.
Upon entering this biome you get the achievement"The Whispering Towers".
Forest - This biome variant is often lower than the standard and slightly hilly. The variant is also filled with larch, pine, spruce, fir, and maple trees. Small bushes, and thistle plants, and sometimes poppy flowers, bluebells and wheatgrass also spawn here. The ground is made up of grass, podzol, and barren dirt. Lakes are rarer in this variant than in the standard. Rabbits, birds and butterflies spawn commonly. Fallen leaves are common on the ground for any of the standard trees. Mountains spawn in this region also, but it is rare.
Forest Light - This biome variant is almost identical with the normal forest variant, but has less vegetation.
Larch Forest - This variant is a forest dominated by larch trees.
Maple Forest - This variant is a forest dominated by maple trees.
Pine Forest - This variant is a forest dominated by pine trees.
Standard - This biome variant is the standard variant, but can include all that is found within the other biome variants, but has the ability to spawn wide open plains very rarely.
Like with many major mountain ranges, gemstones are twice as common underground in the Mountains of the Wind as compared to most biomes, making mining here incredibly profitable. They are slightly less common in the foothills, though they are nonetheless more common there.
In addition, the ground in these Mountains is dotted with clay, of both the regular and cyan varieties.
Although named by Tolkien and therefore "canonical" in a loose sense, this mountain range was only mentioned in early versions of the Legendarium and appears only on one of the Ambarkanta maps, Map IV, which shows Arda before the War of the Gods (in which the Valar laid waste to Utumno and captured Melkor). The Mountains of the Wind are located at the equator and form a partial boundary around the land of Hildórien.
The mountains are not depicted on the subsequent Map V, "After the War of the Gods", which shows the general shape of Arda following those cataclysms (and which does depict the Red Mountains). Therefore it is not certain whether or not the Mountains of the Wind still existed in the Years of the Trees, let alone in the late Third Age. Map V forms the basis for the whole-world maps of Arda in Karen Wynn Fonstad's Atlas of Middle-earth and the map in this mod.
A further consideration is that Tolkien drew the Ambarkanta maps long before forming the vast majority of his created world, including not just the writing of The Hobbit, but also the Rings of Power, the entire conception of Second and Third Ages, and the familiar map of the Westlands of Middle-earth. He never again drew maps of ancient Arda. Given his tendency to constantly revisit and revise parts of his earlier work, it is not clear if Tolkien would have chosen to keep the Mountains of the Wind in a hypothetical "post-LotR" map of the whole world.
However, given that there is no reason to believe the Mountains of the Wind would have been excluded from the mature Legendarium, and that their existence does not conflict with anything else, they have been included in the mod's map.