To be fair, in the Midwest this is often because there used to be a diet of much more flavorful freshwater fish from local lakes, but overfishing destroyed their populations and pushed prices way up, forcing cuisine to adapt to cheap saltwater fish.
I see big fillets of salmon and other large fish in Krogers, from the large industrial supply chain, next to the occasional little trouts and whatevers, and I often wonder "where do those little guys come from? How is it possible for them to get into this case?"
I'm not at all aware of any fresh water/river fishing companies, it strikes me as unsustainable except on a semi-recreational basis.
[1] https://commons.wikimedia.org/wiki/Category:Lake_Erie#/media...
I'm not an avid fisherman, but anybody who is should seriously consider visiting Mongolia before it's too late. An exceptionally brutal winter in 2009 killed many livestock and drove millions of people to the capital city. And in the past 10 years the mining industry has exploded. The population is rapidly moving away from nomadic pastoralism and toward industrialization and private property. While I'm sure most of the country will remain undeveloped for quite some time given its size, with the mining operations the waterways are likely to become increasingly suspect.
FWIW, it's not that Mongolians are like some isolated tribe in the Amazon. They're fully aware of the world and enjoy a decent literacy rate. But the Soviets kept the Mongolian economy relatively undeveloped, perhaps because the pastoral culture fit the communist ideal. With the collapse of the USSR the country stayed on the same course until about 10-15 years ago when outsiders (especially South Koreans) poured in to develop the resource extraction industries.
The principle grain is (I think) wheat, often as Russian-style dumplings. Filled with mutton, of course.
The food is pretty simple. Nothing flashy. Not many ingredients. The steppe is a pretty desolate place. Not necessarily bland, either, though. The homemade camel soup was made from dried camel meat seasoned with a wild herb (maybe some kind of allium-related weed?) the host collected while tending his livestock and packed into jars with salt. (Perhaps it pickled a little?) Another dish at a small restaurant was stir-fried horse meat with garlic shoots.
I did eat sheep brains, scooped out of a whole cooked sheep's head sawed in half. That was at a restaurant in Ulaanbaatar. Memorable but definitely the most bland dish I ate there.
I had many other dishes but my memory fails me. Oh, I did have tea with camel's milk on a couple of occasions. Never got to try the famous fermented (alcoholic) horse milk, though.
About the dumplings, I was just recently reading about manti [1], a Turkish dumpling (which is basically steamed or fried balls of dough filled with ground meat or other fillings).
[1] https://en.wikipedia.org/wiki/Manti_(dumpling)
The Wikipedia article said it may be of Central Asian or Turkic / Mongol origin, and had spread to many countries, including Central Asian ones, the Caucasus, Russia, etc. I'm guessing the Russian-style dumplings you mention are a form of manti.
Edit: Just looked it up again, the manti article links to buuz, the Mongolian name for it:
https://en.wikipedia.org/wiki/Buuz
Also, do they eat much of vegetables, fruits, etc.?
Mongolia is pretty large. IIRC the south is mostly desert, the east more grassy plains, and the west very mountainous. I'm sure the cuisine varies. Nonetheless, AFAIU steppe cultures have very similar diets--heavy meat consumption, particularly sheep, goat, camel, etc.
My wife and I went in 2012 for about a week. Most of that time was spent with expat family working in Ulaanbaatar, where we took a few excursions to parks and monuments not too far from the city.
We took a 3-day trip to the Gobi Desert on a very typical itinerary where you hire a driver and translator and stay with a few host families. Because of tourism and the mining industry, the Gobi families were settling down more. Our host families, while still remote and dispersed, lived in Gurs that hadn't been moved in years. (Whereas traditionally you moved roughly once a year, cycling through grazing areas.) At the time travel books recommended the Southeast for a more "traditional" experience. But you really shouldn't miss the Gobi if you're doing a family trip or a short tour.
I'm hardly particularly knowledgable about the country or culture. But what was most striking was how the land was open and accessible--so very little private property, with the legal right for natives and (IIUC) visitors to roam and camp where ever they please so long as they're not disturbing anyone else.[1] It's basically a dream for anyone who loves the outdoors. I'd hardly classify myself as a world traveler, nor an avid outdoorsman. But I have hiked and camped rural Ecuador and visited rural parts of Borneo. The sense of openness, freedom, remoteness, and safety in Mongolia just seemed incomparable to anywhere else. But who knows how long that will last.
[1] There's an imaginary boundary (if not a fence) around a Gur or collection of Gurs that demarcates de facto private from public land. And Mongolians traditionally keep a native breed of guard dog for protection, so you're encouraged to get vaccinated for rabies. But outside the cities families are so dispersed (on the order of miles) that you're unlikely to accidentally intrude upon anyone's space.