One theory is that mountains are formed by the collision of tectonic plates. When two tectonic plates collide, one plate is usually forced beneath the other, and the resulting uplift can create mountains. This process is known as orogenesis, and it is responsible for the formation of some of the world's largest mountain ranges, such as the Himalayas and the Andes.
Another theory is that mountains can be formed by volcanic activity. When magma from deep within the Earth rises to the surface and erupts, it can build up over time to form volcanoes. If the volcano is large enough, it can eventually become a mountain. Some examples of mountains that were formed by volcanic activity include Mount Fuji in Japan and Mount Kilimanjaro in Tanzania.
Finally, mountains can also be formed by erosion. Over time, the forces of wind, water, and ice can wear away at the surface of the Earth, creating valleys and canyons. In some cases, these valleys and canyons can become so deep that they eventually become mountains. An example of a mountain that was formed by erosion is the Grand Canyon in the United States.
In conclusion, there is no one definitive answer to the question of when The Mountain was created. However, the three theories discussed above provide a possible explanation for how mountains are formed.