See? This. I have a hard time believing a system with a 970 can run the game well at 4K30. Your 970 has .5 GB more usable VRAM (at least that it has fast access to) than my 1060 and is otherwise inferior. Unless your definition of can run is drastically different than mine, part of my system must be broken because mine chugs at that resolution
Solid 30 fps, I was shocked that it runs so well.
How much ram do you have? This game appears to be quite intensive on system memory and VRAM.
I remember running it at this before the latest performance patch and was flabbergasted. MSAA had to go, but I was, and still am able to run the game at 4K 30 fps with custom High settings, the custom High aspect is something I forgot to mention.
It was obscene to me, as running High-Ultra settings at 1080p 60 was a struggle at that point in time as there were some occasional dips and stutters to the mid-low 50s, yet I was able to run the game at 4K 30 fps with the same graphical settings at a solid 30 fps, at 4K 30 fps my GPU is pushing 2x more pixels than 1080p 60, it didn't make much sense to me and deeply implied that the game was failing to utilize the CPU properly when trying to run the game at 60 fps. Fortunately this is no longer the case and I am able to run the game at 1080p 60 fps with slightly higher settings then I have on display below.
These are the settings I'm using right this moment for 4K 30, there might be some wiggle room here but I haven't really tested 4K lately so I'm not too sure.
My 1080p 60 fps settings are quite similar to this, with maybe two or all of the reflection settings on Ultra:
Ignore the Snow quality setting, I don't have Blizzard Mountain so I have no idea how it performs with it set to Ultra.
You have a GTX 1060 3GB, which has 128 less cores and 3GB less VRAM than a GTX 1060 6GB, at the same clock-speed a 1060 6GB is theoretically 11.1% faster.
My GPU at 1535MHz would be theoretically 10.8% faster than a GTX 1060 3GB at 2GHz.