Stock up on groceries. Print off driving directions. And be very, very patient.

Small towns and rural enclaves along the path of April's total solar eclipse are steeling for huge crowds of sun chasers who plan to catch a glimpse of day turning into dusk in North America.

Tourism and community leaders in the path of totality from Texas to Maine have trucked in extra fuel and port-a-potties, and urged residents and visitors to be prepared. Some counties have issued disaster declarations to get extra help with policing and other aid, similar to the aftermath of severe storms. And in Oklahoma, the National Guard will help.

Because of expected heavy traffic and other disruptions, hundreds of schools are closing or switching to remote learning in states including Texas, Indiana, Ohio, New York, Pennsylvania and Vermont.

Why all the warnings?
Look no further back than the last U.S. total solar eclipse in 2017 to understand the concern, said Tom Traub, who is part of NASA's eclipse ambassador program.

That year, he traveled to Beatrice, Nebraska, where the normal population of around 12,000 swelled to around 40,000 as eclipse watchers arrived.

“You had gas stations running out of gas," said Traub, who also serves on the board that runs the Martz-Kohl Observatory near Frewsburg, New York. “You had restaurants running out of food. You had restrooms that were full and closed.”

This time around, top viewing locations want to avoid a repeat.

“They are preparing for mostly a worst-case scenario," he said. "And hopefully that won’t be the case.”

Cellphones might not work
In Central Texas, emergency officials in Hays County recommend a "solar eclipse survival bag” stocked with items including a mobile phone and charger.

The bag, the instructions advise, also should contain a hard copy of maps and a compass — “goin’ old school!”

The reminder to bring a fully charged phone — but to expect possible jammed signals — is widespread in prime viewing spots. In 2017, drivers using their cellphones to share photos and navigate through traffic overwhelmed towers.

“Write down key phone numbers just in case,” advised the Lyndon B. Johnson National Historical Park, about 50 miles east of Austin.

Stock up on fuel and food
Don't wait until the last minute to buy groceries is common advice from several Texas counties that have issued disaster declarations so they can get get extra help with the crowds.

Among them is Kerr County, located 65 miles northwest of San Antonio in the heart of the Texas Hill Country, where the normal population of 53,000 is expected to double or triple.

“Make sure your vehicles are tanked up, that you have sufficient grocery supplies, that your prescriptions are filled and that you are stocked up on provisions for any animals in your care,” Rob Kelly, the county's top official who signed the disaster declaration, said in an online post.

Preparations in the air and at sea
Even smaller regional airports are getting ready. In Cape Girardeau, Missouri, extra fuel is being hauled in, said airport manager Katrina Amos.

The airport was caught off guard in 2017, when the city of around 40,000 along the Mississippi River also was in the path of totality.

Between 40 to 50 extra planes landed that day. ‘We didn’t expect this,’” said Amos.

This year, volunteers have signed up to help park all the extra planes that are expected. There also will be hamburgers and hot dogs, Amos said.

Offshore, the Coast Guard will have boats patrolling in Lake Erie; it's along the path and some boaters plan to watch from the water.

Brace for traffic
It will be all hands on deck at fire departments in the path of the eclipse, said Dr. Brad Raetzke, an emergency room doctor in Columbus, Ohio, who also is a medical director for several fire departments in the area.

He's concerned about eye injuries if people stare at the sun without protective glasses. And with all the extra traffic, there also will likely be more crash injuries, said Raetzke.

In 2017, he went with his family to Nashville, Tennessee, to watch the eclipse. The return trip took 15 hours, instead of the typical six. “So I can understand the importance of planning,” he said.

In Erie, where hotels are nearing capacity, residents are urged to leave the interstates to visitors, with signs posted more than 150 miles outside the city limits warning of delays.

Traffic will be "just almost nightmarish once totality ends,” said Chris Temple, the VisitErie spokesperson, who has been in meetings for more than a year planning for an onslaught of visitors that could double the size of the city of 94,000.

Despite the hassles, the city's tourism slogan to get eclipse-ready — SHINE — ends with a reminder. “Enjoy the moment," said Temple.