Wind and hydro are more of a western thing, the eastern grid probably relies more on gas and coal as well as nuclear.
<https://www.chooseenergy.com/data-center/electricity-sources...>
Coal ranges from a high of 93% in West Virginia (not terribly surprising), to nil in CT, DE, MA, NJ, NY, RI, and VT.
Nuclear does contribute a lot, up to 50% (IL).
New York's hydro, Niagara Falls notwithstanding, is still only 17% of total (though NY is a large energy producer). Vermont is 48.2% hydro, 28.3% wind, and 10.2% solar, though it would be the smallest producer in the north-east.
Even the south-eastern states tend to use much less coal than I'd have thought.
This page shows a graphical depiction of generation sources for states. It's still a bit muddled, but several Eastern states are among the highest in renewables usage, with Vermont leading the country:
<https://bigthink.com/strange-maps/electricity-generation-by-...>
Original source is Visual Capitalist:
<https://www.visualcapitalist.com/sp/road-to-decarbonization-...>
Jpeg: <https://www.visualcapitalist.com/wp-content/uploads/2021/08/...>
You know, it was only the largest battery in the world for like 30 years...