Awesome! I had been working on a similar project couldn't figure out the snow on the trees for the life of me! It's great to see how you approached it. The work look great! Thanks for sharing your process.
I believe author would be surprised that it's not american, but soviet bunker :)
Have a look at some of the ZBrush work behind Epic’s Paragon characters. Kevin Lanning, the Lead Character Artist on Paragon, launched an amazing thread on ZBrushCentral that will allow the team to start sharing some of the Zbrush modeling work the team has done for recent and upcoming Paragon Heroes/Skins.
Paragon is the Epic’s third person Free-To-Play action MOBA that is currently in open beta on PS4 and PC. It appears that the character team behind the game is quite huge and there’s a reason for that.
Make sure to check out other artworks here.