GRUNDY, Va. – Sandra Cook got in line midday on a recent Friday for dental care that she wouldn't receive until the next morning. Hundreds more like her showed up at Riverview Elementary and Middle School, many planning to spend the night, just as buses brought kids home and volunteers arrived by the hundreds to turn the school into a makeshift dental, eye and medical clinic run by Remote Area Medical, a nonprofit charity program.

Many people in this southwestern corner of Virginia struggle to pay for everyday needs, and that includes basic health care.

"My teeth and my eyes are really bad," said Trey Justice, who walked five hours to reach the school and set up a tent to spend the night. "I got ran over about four years ago. Nothing but pins all over. Don't have no doctors, no insurance."

Six years after the passage of the Affordable Care Act, and despite 20 million more Americans gaining health insurance, considerable gaps in health care remain.

The decision by states like Virginia not to expand Medicaid and the lack of dental and vision coverage even for those with insurance have meant that the demand for RAM's free mobile clinics has stayed strong.

On a Saturday morning, the sun had yet to rise when RAM founder Stan Brock called the first wave of patients into the pop-up clinic.

Brock founded the charity care program in 1985 to bring health care to people in developing countries. But he expanded the project to the U.S. when he realized the depth of the need here.

The torrent of patients is a measure of the poverty and isolation in this rural area: 15 percent of adults are uninsured; 1 in 5 lives in poverty; and the unemployment rate is more than double the state average.

Over the weekend, nearly 1,000 teeth will be pulled, 400 pairs of eyeglasses made and more than $1 million in health care services delivered.

Gary Owens, 55, a laid-off coal miner who is uninsured, has paid out of pocket in the past for health care but he's been unable to afford the blood tests to figure out what's wrong with him. The doctors here worry the reason he recently lost 25 pounds is that he might have cancer.

If Owens lived a short drive away in Kentucky or West Virginia, he'd be eligible for Medicaid.

State lines are now often the difference between poor people having health insurance or not. After Kentucky expanded Medicaid under the Affordable Care Act, the percentage of uninsured poor adults dropped from 40 percent to 23 percent in one year.

Studies have found that people in Medicaid expansion states are more likely to have a regular doctor, get vaccinated and receive treatment for chronic diseases. But in states like Virginia, uninsured poor adults often must turn to the emergency room when they need help.

Doreen Facey-Biggs, a nurse volunteering for the weekend-long charity clinic who is originally from Jamaica, said the choices people face seem at odds with America's standing in the world. "I've been in this country a long time, but I'm still amazed at the differences and the disparities in health care services," she said. "That in this rich country, this first-world country, so many people have no insurance."

That's the case for James Love. He lives along a mountain road with his wife and two adult children, tending to his animals and working multiple jobs to pay the bills.

Love has to make tough choices when it comes to paying for medications for high blood pressure, high cholesterol and nerve pain. "You choose what you can afford," he said. "You not only have to do it for you, your wife, your children, sometimes your grandparents, your parents."