On Aug. 21, a swath of the USA will plunge into darkness. The highly anticipated solar eclipse will cross 12 states from Oregon to South Carolina, and travelers are clamoring to get into its path.

We asked USA TODAY Network reporters to tell travelers what to expect in their regions, and how to find accommodations (hurry, they’re going fast!)

But don't worry if you can't get a room. There are also plenty of viewing parties going on all over the country. Moving from west to east:

OREGON

The first state to see the total solar eclipse Aug. 21 at 10:15 a.m. local time is also going to see big crowds traveling into the 67-mile wide path of totality. Between 1 and 2 million people are expected to swarm the state, along with thousands of Oregonians.

Most hotel rooms and public campsites are sold out, some reserved more than a year ago. But, as of Friday evening, there were still a few options available for people who caught eclipse fever late in the game.

Among them are public universities. Here are a few options.

Western Oregon University, Monmouth: The Wolves are renting out their football field/track area for tent camping and recreational vehicles. There were 25 tent camping spaces and 12 RV spaces still available. Prices are the same for both, $150 for Saturday and Sunday, and an additional $40 per night for Thursday, Friday and Monday. Campers have access to portable restrooms, gym showers and hand-washing stations. Linens — a mattress pad, pillow, blanket, sheets and towels — are available for $10 per night.

Eastern Oregon University, La Grande: For $500, tourists can stay in the residential dorms from Saturday through Tuesday. The college only made room available to rent starting July 21. Each room includes a kitchenette, full refrigerator and microwave and can accommodate up to five people.

Oregon State University, Corvallis: For solo or couple eclipse watchers, OSU still has on-campus housing available. They are traditional dorm rooms with a common bathroom and showers on each floor. The rooms come with a commemorative tailgate blanket, indoor pool and full kitchen access, wireless Internet and cable television in the lounges. The price for a one-person room is $265 minimum for Saturday and Sunday nights, and $132.50 each for Friday or Monday. Two person rooms are $375 minimum and $187.50 for each extra day.

Some spots at campgrounds are still up for grabs.

Eclipse Camp, Jefferson: A private campground located near the center of the path of totality still has a couple dozen sites available, according to its website. One 30- by 40-foot camp spot would cost an eclipse watcher $499 for four days and three nights. This spot boasts a small convenience store, central garbage area, “luxury” portable restrooms and complimentary eclipse glasses.

On public land: There are a few options for campers who want to head out to a national forest in the path of totality (Siuslaw, Willamette and Deschutes national forests). First, they could grab one of the sites in the area that cannot be reserved ahead of time. These are mostly at small campgrounds scattered about, but campers would have to claim their spot early — perhaps up to 14 days in advance of the eclipse since that is the maximum stay length allowed at a national forest campsite. The other option is to camp at a non-designated campground, which is known as “dispersed camping.” People typically do this on the side of Forest Service roads or by hauling gear to a specific spot. On public land, people are largely allowed to stay wherever they want, though forest officials request that they refrain from leaving a mess behind.

— Connor Radnovich, (Salem, Ore.) Statesman Journal

WYOMING

Headed to Casper, Wyo., for the celestial spectacle of a lifetime?

Procrastinators, rejoice: Whether you're looking for a motel room or just a place to pitch your tent, you still have a few options for a place to stay.

One caveat: It'll cost you.

The total solar eclipse will come to Casper at 11:42 a.m. The big event will only last 2 minutes, 26 seconds, but organizers of the Wyoming Eclipse Festival expect thousands of visitors to flood Casper over the weekend leading up to the extravaganza.

Lodging options are dwindling so make your lodging reservations now.

Here's what's going on with hotels and motels.

Prepare to spend big. One motel just raised its nightly starting rate from $890 to $1,495.

The good news is that festival organizers are continuously updating the event website as rooms fill or become available, so you can be reasonably sure that any place listed under "hotels" still has at least one room left.

It's best to call the hotel or motel directly to book, says Anna Wilcox, the festival's executive director.

Camping could be a good alternative.

The greater Casper area has campgrounds aplenty, but you'll almost certainly need to make a reservation and pay up. Even campgrounds that don't usually require reservations are using a reservation system for the eclipse, Wilcox says you'll have to call or make a reservation online. Fees range from as low as $10 to upward of $300.

One exception to the reservation rule is a group of Bureau of Land Management campgrounds in the area. The four campgrounds are first come, first serve and range from free to $10 per night. If you want to snag a spot, arrive early and come prepared with a backup plan.

The eclipse festival lists available campgrounds on its website.

If all else fails, try Airbnb and Craigslist.

A quick Airbnb search for Aug. 20 to Aug. 22 in Casper brought up 111 rentals ranging from camping spaces to backyard teepees to rooms to entire homes. Some are going for $68 a night. Some are going for more than $5,000. Many Casper residents are also renting out their backyards for camping, Wilcox says.

If you'd rather go the Craigslist route, pull up the Wyoming Craigslist page — yes, there is a single Craigslist URL for the entire state of Wyoming — and search in "sublets/temporary housing" or "vacation rentals." Prices range widely, depending on how fancy you want to get.

But, like any Craigslist transaction, use common sense and discretion. The Pinedale resident looking for an "Eclipse weekend with attractive young women" may be best avoided.

-- Jacy Marmaduke, The Fort Collins Coloradoan

MISSOURI

The Hotel Phillips Kansas City, Curio Collection by Hilton is offering guests a Great American Eclipse package. Kansas City is in the direct line of the eclipse. Hotel Phillips’ package includes a one-night stay at the hotel, Total Eclipse viewing glasses, a dark chocolate amenity, and valet parking for one night. The package starts at $329 a night.

More eclipse coverage:

Here's the only way to get an unobstructed view of the eclipse

How to take the best photos and videos of the solar eclipse

'Eclipse blindness' is a real thing. Here's how to watch the solar eclipse safely

TENNESSEE

Nashville hotels are offering special packages for guests who want to witness the total solar eclipse. Hotel rooms are selling out, so here are five packages to help you get your search started:

Residence Inn: Located in Music City's West End, Residence Inn's Total Solar Eclipse package includes a pair of eclipse glasses, two cocktails, Wi-Fi and a complimentary hot breakfast buffet. Rates are per room, per night and based on availability at the time of reservations. Use the promotional code ZJL when making an online reservation or call 800-228-9290.

Union Station Hotel: The Union Station's package includes overnight accommodations for two on Sunday and Monday nights, eclipse viewing glasses, commemorative champagne glasses, Moon Pies, Astronaut Ice Cream and a champagne brunch party on an outdoor veranda. Overnight valet parking is available. You must book a two night minimum stay for this package at $478.21 a night. An upgrade to a suite gets you all of the above plus a limited edition Nashville Total Eclipse poster, access to a local astronomer to talk about the phenomenon — and a personal telescope engraved to commemorate the day. A two-night minimum stay in a suite is necessary at $821.17 per night. For more information visit Unionstationhotelnashville.com.

Loews Vanderbilt Hotel: The hotel offers one set of eclipse viewing glasses, one solar eclipse commemorative T-shirt, one $25 Uber gift card and a $24 Mason Bar credit to use during your stay. This package starts at $349. For more information visit Loewshotels.com or call 800-235-6397.

SpringHill Suites: SpringHill Suites' Total Solar Eclipse package includes a pair of eclipse glasses, two cocktails, Wi-Fi and a complimentary hot breakfast buffet. Rates are also per room, per night and based on availability at the time of reservations. Use the promotional code ZJL when making an online reservation or call 800-228-9290.

Choose your own Music City Solar Eclipse Package: This package includes a minimum one-night stay at a participating hotel, plus a Nashville Solar Eclipse gift bag with eclipse viewing glasses, a Music City note picnic blanket and a Nashville T-shirt voucher. Just choose your hotel stay dates on Visitmusiccity.com, select a hotel and room and the number of guests.

— Tabitha Waggoner, The Tennessean

SOUTH CAROLINA

Here’s what you will find by city:

Greenville: Most, if not all, hotels in the Greenville area are booked that Sunday before the solar eclipse. Laura Connell, leisure travel and community outreach marketing coordinator for Visit Greenville, recommends trying to get on a hotel’s wait list in case a room becomes available.

Anderson: In Anderson, where the full eclipse will last more than two and a half minutes starting at 2:37 p.m., hotels have been sold out for several weeks. Glenn Brill, director of the Anderson County recreation department, says he is referring people inquiring about rooms to Spartanburg, where an edge of the county’s west side will have a view of the eclipse. People cannot park overnight at the Civic Center of Anderson, where the county is hosting one of its two eclipse parties. But they will be able to start parking there at 4 a.m., Brill says. The county is also hosting a viewing at Green Pond Landing on Hartwell Lake, where the gates will open at 8 a.m. Other daytime viewing spots in Anderson County include the city of Anderson’s recreation center and Wren Park, the Belton Center for the Arts, Denver Downs Farm, the Jockey Lot flea market and the Blue Jar Barn.

Columbia: Jason Outman, executive director of Experience Columbia S.C., says his visitors' bureau has conducted an informal survey of hotels around town, and all were booked on the Sunday night before the eclipse. They were at about 90% occupancy on that Monday. Outman says, though, that this survey represents just a small sample of the capital city’s 126 hotels. Customers may get lucky, he says, if they call hotels directly to find a room. Another option for those visiting Columbia for the eclipse is the State Fair Grounds, which has parking for more than 4,000 cars. Visitors can sign up for a space to park their RVs for a fee of $125 at Scstatefair.org/total-eclipse-parking.

Charleston: There are few rooms left In Charleston, where the eclipse is expected to cross about 2:48 p.m. Monday. The Charleston Visitor’s Bureau is seeing about a 90% occupancy rate at this time through the weekend of the eclipse, a representative says.

AirBnB: According to Airbnb.com, bookings for the room-sharing site are up dramatically across the state—almost 400% over last week. More than 6,700 guest arrivals have already been booked, with the most popular cities being Charleston, Mount Pleasant, Greenville, and Columbia.

— Maayan Schechter and Anny Mitchell, The Greenville (S.C.) News

More eclipse coverage:

School's out for the eclipse: Why class is canceled for many in the South on Aug. 21

Street lights could hinder eclipse for some viewers

Where could clouds ruin your view of the solar eclipse?

ECLIPSE PARTIES

If you don’t need a place to stay overnight and just want to hit an eclipse party, here are a few options around the country.

The Anvil Hotel in Jackson Hole, Wyo., is hosting a viewing party in its parking lot. Starting at 9:30 a.m., the hotel will offer Moon Dust lattes and a Moon Flow yoga session. At noon, there will be a tailgate lunch with live music hosted by the on-site Italian restaurant Glorietta. Guests will receive special glasses, yoga mats and a time lapse video of the event.

In Chicago, where the eclipse is slated to start at about 11:54 a.m., The Godrey Hotel Chicago is having a viewing party at its rooftop lounge. Executive Chef Nathaniel Cayer will craft The Eclipse, a special frozen cocktail that goes from light to dark. Doors open at 11 a.m., and guests will be seated on a first come, first serve basis. Groups can also reserve a table by emailing Eclipse@godfreyhotelchicago.com. Neighboring offices that RSVP can enter to win a free one-hour office party. The first 100 people to arrive will receive complimentary eclipse-viewing protective eyewear.

Even New York City is getting into the eclipse action. New York will only get a partial eclipse, with 71% of the sun covered by the moon. The first contact of the moon passing in front of the sun is at 1:23 p.m. and the maximum coverage is at 2:44 p.m. Final contact is at 4 p.m. Classic Harbor Line is ferrying people out into the harbor for views of the eclipse by the Statue of Liberty. Guests are asked to bring eye protection and to not look directly at the sun if they don’t have any. More information on the afternoon Solar Eclipse Cruise can be found at Fareharbor.com.

— Nancy Trejos, USA TODAY