This is a map from 2015, and it was mostly nonsense back then.
The map appears to date back to an article from US broadcaster CBS in 2015. It claims to have used data from the Federal Emergency Management Administration (FEMA), Medicine and Global Survival, and the National Resources Defense Council. FEMA, however, has distanced itself from the map. A spokesperson for the organisation said: “FEMA does not, and has not, released any type of formal map of potential nuclear targets. However, FEMA provides information to the public to help them prepare for a potential hazardous or radiological event through Ready.gov.”
https://www.independent.co.uk/news/world/americas/us-map-nuclear-war-russia-b2279249.html
Also from the same source:
Some of the larger targets include active nuclear plants. There are approximately 90 plants across the US, with some located in Alabama, Arizona, Maryland, New Jersey, Pennsylvania, and Tennessee.
That's just silly. What's the point of nuking a nuclear power plant? It's important electricity infrastructure, sure, but other than that it makes zero sense (it's a hard target, typically remote from anything else you might want to break) - and there are lots of other electrical infrastructure sites that make far more sensible strategic targets (such as hydroelectric dams, whose destruction also targets downstream infrastructure and industry, as well as water supplies), and it makes little sense to cut power to cities and/or industries that have ceased to exist.
The four kinds of targets I would expect to see in a nuclear strike are (in order of priority):
Any site that makes a rapid nuclear counterstrike possible - ICBM silos, airfields that host or can host nuclear capable bombers, SAC command and control sites, submarine ports and naval infrastructure, etc. - If you don't get all of these very quickly indeed, you're seriously fucked, and will not be winning any wars today.
Any site where conventional forces are concentrated - Army bases, Naval Bases, Military airfields, Large civilian airfields that could readily be used by the Airforce, Coastguard facilities, National Guard assets, etc. - You need to get all of these too, because revenge can easily be served cold if there's no nuclear option.
Civilian and military command and control infrastructure - The Capitol, Whitehouse and Pentagon; New York City, Chicago, Los Angeles; Other large cities with major centres of government (including all state capital cities)
Commercially important locations - Ports, Airports, major business hubs (such as the stock exchanges in New York, Chicago, Boston, Minneapolis, Kansas City), Industrial areas, particularly those associated with military production, or with oil and gas distribution, refining, etc.
Obviously there's a lot of overlap; Major commercial ports, for example, are also actual or potential naval and/or submarine ports.
Beyond these classes of target, there's not much point in using nukes. If you hit these, there's nothing left that can hit you back, or can rebuild the means to hit back, or can coordinate that rebuilding; and destroying the rest is counterproductive - presumably your long-range objective is to seize territory and/or resources, and that's easier if it's not all a radioactive wasteland. If your objective is simply to eradicate the US as an effective international power, commercially and militarily, that lot is more than enough to achieve that objective. Although it wouldn't be easy to do without getting mutually destroyed - indeed, you would be MAD to attempt such an attack. I can't see any plausible way to strike all of the first priority targets effectively and rapidly, particularly not the SLBM forces.
