In these four USA states, Montana, Wyoming, North Dakota, South Dakota covid19 cases are minimum ? Why ? Since these four states are in the far north in mainland USA, so geographically their weathers are probably dry and relatively cool by being far from the oceans and great 5 lakes of USA. Due to being far north in US map, air evaporation is minimum ! According to my hypothesis covid19 is mainly in oceans along with intermediate hosts as some marine animals they accumulate in ocean water and by evaporation and wind covid 19 viruses are distributed all over the world but viral density is mostly in cities bordering or near to oceans and big seas.
The factors can be manifold. First of all, the lack of large cities and a limited number of external travelers may have limited the contacts and the diffusion of the infection. Climate factors may also have played a role.
Dear Sinan Ibaguner, I am not sure about the scientific basic of your hypothesis honestly, but even if that would be true, I would not expect this to be so significant to be mentioned about the difference in these 4 countries compared to the others. There are much more likely explanations, in my mind. Indeed, density in population, communication with other regions, weather and so on.
Your observation is not a universal trend around the world Sinan Ibaguner
In my country, Johanessburg is inland, 600 kilometres away from the nearest ocean but it is the epicentre of the outbreak (at the time of writing this response). Durban is a coastal city, but is (at the time of writing this response) far behind Johannesburg. Cape Town is a coastal city and has had more cases than Durban and was the epicentre up until a few weeks ago, but its caseload is much lower than Johannesburg.