Given a travel related situation, and given a specific question about the situation, summarize the question into a title

I will be going to Nepal for mountain trekking, I want to bring USD simply because it is very hard for me to get Nepalese Rupee in my home country. 

At tourist heavy sites, do most stores accept USD? If no, can I get Nepalese Rupee easily at local currency exchange centers?

Do stores at tourist-heavy sites in Nepal accept USD?