I've been hunting and fishing in Mongolia. Back before I met my wife, I dated a Mongolian gal for a while.
The fishing can be amazing if you get away from other people. A lot of Mongolians don't seem to know the difference between the river fishes, and I saw people keeping taimen under 18", which I believe was illegal. Also, a lot of the fish had weird parasites.
We hunted marmots and gazelles. I was warned not to touch the wildlife because of the risk of plague.
The landscape has changed a lot due to mining activity. Some places that used to be pristine, beautiful, and wild, are now covered by mountains of overburden from strip mining. You can still find some amazing untouched places, but it requires more work these days. I was mostly fishing for grayling, and I found some nice spots I could have to myself. Guided taimen fishing and the ibex and maral stag hunts are way out of my price range. But it's loads of fun to just take a tent and a fishing rod and go camping somewhere near a river. There are also abandoned Soviet military bases where you can scrounge for souvenirs.