So, the problem I see with this picture is that the snow on the mountains is much brighter than the sky. Except for those rare instances where the light is behind the viewer and the clouds are dark over the horizon, the ground is just about always less-bright than the sky. In this case, I'm assuming you took 5 shots within a short period of time. That means that the mountains were illuminated by the sky. So, they can't reflect more light than they are being hit with... which means that the snow highlights should be no brighter than the brightest part of the sky. The reason this picture just screams "I'm made from two pictures" is because we humans recognize that the snow shouldn't look brighter and whiter than the sky. Even if we don't know it, our brain is asking, "Why is the snow white, when there's no white light around?" It makes us suspicious. Same reason some HDRs look artificial.
Anyway, if you have 5 shots at -1, -1, 0, +1, +2, this could be a good candidate for HDR.
Otherwise, you need to do something about the blown-out whites in the snow and the creek.
~P