Conversation so far:
why do you think the state of himachal pradesh is called so
Himachal Pradesh is located in the ranges of Himalaya commonly known as the Himachal range.
any more reasons why the state of Himachal Pradesh is called so?
The Jammu and Kashmir states border the Himachal Pradesh in the North and the term Himachal indicates abode of snow. Accordingly, Himachal Pradesh is also granted a name Himachal.

Question: who came up with the state's name?
Self-contained rewrite: who came up with the state of Himachal Pradesh's name?