Once the polls begin to close Election Day, all eyes will turn to the swing states across the country counting votes in the presidential race. And within those states, there are a handful of counties that could hold the keys to the outcome.

Here's a look at some of the key counties to watch across the seven presidential battleground states, ordered by the state's final poll closing time (in Eastern Standard Time).

Georgia (7 p.m.)

Chattooga: One of NBC News' seven communities to watch as part of the 2022 "County to County" project, this northwestern county is rural and has a significant chunk of evangelical voters. Even though then-President Donald Trump lost the state in 2020, his support here grew.

Cherokee and Forsyth: The suburbs and exurbs around Marietta tell a different story, one of reliably Republican communities drifting away from the party in recent years. Mitt Romney won more than 80% in Forsyth in 2012, but Trump won just two-thirds of the vote there eight years later.

Gwinnett and Cobb: It's no doubt much of the discussion election night will center on the Atlanta suburbs. Democrats have run up the score here in recent elections and likely need to keep the double-digit margins up to win again.

North Carolina (7:30 p.m.)

Anson: In addition to running up their margins in big cities, Democrats also need to mobilize voters in the rural South, particularly Black voters. In 2020, Joe Biden won this county by only 4 points over Trump, while Hillary Clinton carried it by 13 points in 2016. If Vice President Kamala Harris is struggling to match Biden's margins with Black voters, that could cost her here.

Henderson: South of Asheville, this county is among those in the federal disaster zone in the wake of the devastation caused by Hurricane Helene in late September. While Trump won this county easily in 2020, his share of the vote dropped 3 points between 2016 and 2020 (from 62% to 59%), and he wasn't able to hit the 63% Romney got in 2012. Trump could help defend against the Democratic push for an upset here by finishing closer to the GOP's 2016 or 2012 marks. Nikki Haley outperformed her state vote share here in March's Republican presidential primary.

Nash: East of Raleigh, Nash has been decided by razor-thin margins in the past few presidential elections (Trump won it in 2016 while Biden won it in 2020). It's also home to a competitive congressional race.

Wake: Home to Raleigh in the fast-growing Research Triangle, Democrats have been building up their leads here and will need to continue to do so if they want to flip North Carolina.

Pennsylvania (8 p.m.)

Bucks: One of the key collar counties in the Philadelphia suburbs, it's one where, as Dave Wasserman, senior editor and elections analyst at The Cook Political Report with Amy Walter (and an NBC News Decision Desk contributor), notes in a recent analysis is "Trump’s best opportunity to make progress in the Philly suburbs" because of a higher share of non-college-educated whites.

Erie: Smack dab in the middle between Buffalo and Cleveland, this blue-collar swing county (north of Pittsburgh on Lake Erie) backed Trump in 2016 by 2 points before Biden won it by 1 point in 2020.

Lackawanna: This Scranton-area county swung away from Democrats from 2012 to 2016 before shifting back a bit in 2020 (Barack Obama +28, Clinton +3, Biden +8). The 2024 margin here might be telling as to whether Biden, a Scranton native, was uniquely able to stem the Democratic erosion.

Northampton: Northampton has served as one of the best bellwether counties in recent memory, picking the presidential winner for decades.

Arizona (9 p.m.)

Maricopa: The massive focus on Maricopa isn't a surprise, considering it's home to more than half the state's residents. Democrats have made gains here as they've made the state more competitive by bringing moderate Republican and Hispanic voters into their coalition. While Trump won it by 3 points in 2016, Biden won Maricopa by 2 points four years later.

Michigan (9 p.m.)

Kent: Home to Grand Rapids, Romney won this once-reliable Republican county with 53% of the vote in 2012. Trump narrowly won it in 2016 with 48%, but Biden flipped it four years later with 42%. If Trump can make Kent look more like 2016 or 2012 again, he could be in for a good night in the state.

Wayne: An obvious point of emphasis for both campaigns, as the county is home to Detroit and will be a proving ground for how Harris can perform with Black and Arab American voters. Neither Clinton nor Biden could match Obama's 2012 mark of 73% there.

Grand Traverse: Home of Traverse City, this wealthy area of northwest Michigan has been trending toward the Democrats. Trump would like to reverse that trend this go-around.

Wisconsin (9 p.m.)

Dane: Home to Madison and the University of Wisconsin, this county is all about the Democratic intensity in highly educated college towns. Biden netted 181,327 votes over Trump here in 2020 — up from Clinton’s 146,422 in 2016. And that Democratic gain helped the party flip Wisconsin in 2020, given that Biden won the state by just 20,000 votes.

Ozaukee: North of Milwaukee, it’s the "O" in the "WOW" counties, the nickname for the three suburban counties in the state that have served as an ancestral home for Republicans. Biden’s 43% there in 2020 was the best a Democrat performed there since 1964, as Ozaukee and Waukesha have drifted a bit away from the GOP in recent years.