Here are a few possibilities:
* Marmot: These are large rodents that are found in mountainous areas. They have a stout body, short legs, and a bushy tail. Marmots can be mistaken for squirrels from a distance.
* Bushy-tailed woodrat: These rodents are known for their long, bushy tails and their habit of building nests out of twigs and other materials. They are often found in forests and woodlands.
* Tree squirrel: These are the most common type of squirrel, and they have a sleek body, a long, bushy tail, and a distinctive "scampering" gait.
If you can provide more details about the animal you're thinking of, I might be able to give you a more specific answer. For example, where did you see the animal? What size was it? What color was its fur?