These animals are found in lots of different places in the world, but I have only seen them on the mountain trails outside of Ulaanbaatar. In my research, these deer are often found in mountainous regions near grasslands, making the places where the Mongolian steppe reaches the mountains an ideal spot for them. There is a big population of red deer that lives in a national park about 100km away from the capital city.
These deer are very hearty and adaptable. They can eat all sorts of grasses, bushes, twigs and shrubs, which means that they can endure the winter when the grass is scarce. This species is also suited for different terrains, so they can find food in different areas. Additionally, they are also suited for living at high elevations, which can be extremely harsh for other animals. This makes them well-suited to the environment in Mongolia.
The biggest threat to these creatures is the loss of their environment. As mining is a large industry in Mongolia, the mountainous regions that these animals call home can be greatly threatened. However, I encountered these animals at a national park. In fact, this area has been protected since the 1700s, making it one of the first protected national parks. Of course, these animals are threatened by climate change, specifically droughts and forest fires. Finally, although they are protected, they are still threatened by illegal poaching as well.