Hills or Mountains?

Well, it has been raining and cold here in Helena for the last couple of days. There was snow in the "hills" surrounding Helena, and while I was driving Hubs to work, I was commenting on the snow in the "hills" and Hubs had to correct me. He had to remind me that they are mountains, although they may be the size of what we call hills in Oregon, they are mountains! Well the elevation here in Helena is 4300 ft (Tigard elev. is 160 ft). So Helena is the top of the mountains and the hills are the very top of the mountains. I am used to seeing a mountain (Mt Hood) in the distance. But now I know better than to call the surrounding mountains, "hills".