How do I achieve the color tone effect in this sample photo in Photoshop?

Question

In post-processing, how do i achieve a high dynamic range, but low local contrast, monotone (but not necessarily grayscale) effect for photos? An example would be this "li river" shot, which has a light blue monotone and a soft, low-contrast feel, but fairly high overall dynamic range? Is such an effect possible using Photoshop?

Answer 1

This looks like a simple desaturation, followed by a Hue/Saturation adjustment layer set to Colorize. Probably a bit of Levels/Curves adjustment for contrast.

Answer 2

Looks to me like it could also be a gradient map. Just set the dark end of the gradient to a slightly bluish hue. Gradient maps are often used to warm up black and white photos using a slightly "chocolatey" dark.