Austin, Texas (CNN) Daytime turns to dusk as Natalie St. Clair's phone lights up with text messages. They come from clients across the vast Lone Star State.

One needs a bus from Texarkana to Shreveport, Louisiana. Another traveling from Corpus Christi to San Antonio has to find a hotel room. A third must get to Fort Worth from a small town in the western part of the state. A fourth reaches out from Lubbock to say she missed her appointment in Dallas.

To the stranger at a party who asks what she does, St. Clair keeps her answer vague: "Just feminist stuff." But the truth is blunt, bold and a sign of the times: "I'm an abortion travel agent."

It's a job that emerged after Texas enacted House Bill 2 in 2013, imposing a new round of restrictions on abortion care and abortion providers. Two key parts of the law have been challenged all the way up to the U.S. Supreme Court, which hears arguments in Whole Woman's Health v. Hellerstedt on Wednesday.

It has been called the biggest abortion case to face the high court in more than two decades and could have far-reaching effects depending on how justices rule.

In Texas, the effects of HB2 have already been felt. Unable or unwilling to meet new requirements, clinics across the state have shut their doors. Before HB2, the state had more than 40 abortion clinics; now there are 13, according to St. Clair's latest count. Among the new rules: Doctors must have hospital privileges, and clinics must function like outpatient surgery centers.

In an enormous state that spans 270,000 square miles -- bigger than many countries -- some women are now living in an abortion desert. In Lubbock, for example, they have to travel nearly 300 miles to reach a provider. And the ripple effects don't stop there.

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The farther a woman lives from a clinic, the more complicated it is to get there. Especially if she works more than one job, needs to secure child care or doesn't have a car or money for a hotel. Add to this the wait time to get an appointment, and another wait time after a legally required sonogram. In some clinics, it has taken as long as 23 days to get on the schedule since the passage of HB2, according to the Texas Policy Evaluation Project at the University of Texas.

The longer the wait to get an abortion, the more expensive -- and potentially more complicated -- the procedure. What could have cost hundreds of dollars easily jumps into the thousands. And if a woman is more than 20 weeks pregnant, she has waited too long to get an abortion in Texas. Under HB2, it's illegal in most cases -- and she'll have to travel out of state.

Enter Fund Texas Choice , where St. Clair, 23, works as the operations manager and is the organization's only full-time employee. While other funds have helped pay for abortions for decades , this one answers a different call necessitated by HB2. It's for anyone who doesn't have a vehicle or must drive two hours or more on their own to reach a clinic.

Working out of an office in Austin, St. Clair often wires women gas money. (PayPal would be easier, but it requires a bank account, something many clients don't have.) In rural parts of Texas, just getting that wired money can require travel across multiple towns to reach a MoneyGram at Walmart. She books flights, taxis, bus tickets and hotel rooms. She regularly studies Greyhound routes and bookmarks airline schedules. Once she drove 3½ hours one-way to hand deliver last-minute financial help.

She tells stories of women who offer to sleep in their cars. Hell will freeze over, she says, before she'll let that happen.

"By far these obstacles are greatest for low-income clients living in rural areas -- which are mostly populations of color," St. Clair says. And if they're not native English speakers, the hurdles are even higher.

She talks about the people who have had to miss appointments because their babysitters flaked or their paychecks didn't clear, and then couldn't afford a later procedure.

There was a woman who flew to Albuquerque, only to be blocked by protesters. By the time she got into the clinic, she'd missed her appointment and had to fly home.

Another young woman stood on a rural West Texas road waiting for a Greyhound bus that never showed. St. Clair scrambled to find a way to get her to her appointment the next day. A taxi would have cost $500, so instead she paid one of the client's friends to do the driving. The two arrived at 3 a.m., five hours before the appointment, only to find out she was further along than expected and couldn't afford the procedure that was required.

I heard similar stories from one of St. Clair's allies in this work.

There was the woman with severe diabetes who knew it was unsafe for her to carry a baby. The first-generation American, the first in her family to go to college, who desperately wants kids someday -- but not now. The one whose abuser took off his condom and said, "Now you belong to me."

St. Clair fields about 60 calls a month and manages about 20 abortion trips. While her focus is logistics, she's often a safe sounding board for clients. They thank her for not judging them. Some say they had no idea they could get pregnant. Others tell her about the men who hurt them. Then there are those who want to be reassured they're still Christian.

Her hours are odd, usually at night, so she can be in touch with clients when they're off work. Most people like to text, in part so no one can hear their words.

She works in a closed-down Whole Woman's Health clinic. Others who share the space are like-minded advocates: educators, counselors, spokeswomen.

Down the hall from St. Clair, a reproductive rights policy wonk keeps a Kevlar vest on her bookshelf. It belonged to her late father, who was an abortion provider in South Texas. An FBI agent was assigned to him to monitor threats. The vest is her "talisman," she says, "a reminder of why I do what I do."

The dangers in this work are real. Over the years and across the country, abortion providers have been killed and clinics bombed. One need only think back to November, when a shooting at a Colorado Springs Planned Parenthood clinic left three dead.

Because of this reality, St. Clair's eyes open wide when -- at night -- someone shows up outside the building and incessantly rings the doorbell. The entrance is hidden, a dark hallway outside provides cover, and there's no telling what, if anything, might have been left outside the door.

She reaches out to colleagues, who tell her to call the police immediately. She does. An hour and a half and four calls later, an officer shows up.

On this night, she has a visitor and officer to escort her to her car. On all other nights, she walks out into the darkness alone, holding a phone to her ear. She keeps a friend on the line, just in case something happens.

'What do I do now?'

Nearly 400 miles to the northwest, Angela Martinez stands in front of the place she once thought would employ her forever. She was the clinic director at the Planned Parenthood Women's Health Center in her hometown of Lubbock.

Now empty and undergoing renovation for new tenants, the facility shut down in October 2013, a casualty of HB2.

"We became an example of the assault on clinics. I was devastated," she says of the closure, which left her depressed for months and led her to move back in with her parents. "I had this great job with amazing purpose, and it was gone."

College students, addicts who don't believe they are fit to be mothers and women who already had children would pull into the parking lot. Martinez remembers them arriving in cabs, old jalopies and fancy SUVs — some even with McCain/Palin bumper stickers. Women who might rail against abortion in their social circles, she says, were happy to accept Planned Parenthood's services once they got pregnant.

They would say things like, "I'm a good Christian or I don't believe in this, but my situation is different," Martinez says.

She never judged. She says she was just glad her clinic could provide them a choice, and a safe legal option to do what they thought was best for themselves and their families.

This overriding purpose drove her. Each week she'd pick up a doctor who flew in from out of town to perform procedures on Thursdays. He would arrive incognito, wearing a hat and sunglasses. He'd step into her car and fully recline his seat so no one could see him.

Martinez could handle the anti-abortion activist who knocked on the door posing as a reporter and wrote down her license plate number. She dismissed the plea from one of her brothers that she get a license for a concealed handgun. She could tune out the screams: "Angela Martinez, you're killing babies!"

When dozens of protesters gathered on the sidewalk and their shouts could be heard inside the clinic, she turned up a dinky radio to drown out the noise for patients -- and herself.

"My attitude was, 'I'm going to be fine.' I wanted my employees to be safe," she says. "And I'd rather have a protester yell at me than at a patient."

She's now working on a graduate degree in social work at nearby Texas Tech University, but in many respects Martinez's heart remains in the past, and she still hopes she can one day return to her previous work.

Also in the past, at times, is Dorothy Boyett.

For two decades, every Thursday without fail, she stationed herself outside this Lubbock clinic. Starting at 6 a.m. and for the next eight hours -- rain or shine, snow, wind or heatwave -- she had a job to do.

She says she quietly prayed and passed out Bible tracts and pamphlets about baby development. It was her ministry to offer another way. A London native, Boyett is sweet, genteel, her English accent charming.

This born-again, 69-year-old grandmother of 15 sits at her kitchen table and says she still sometimes forgets on Wednesday nights that she has nowhere she has to be in the morning.

"We had worked for 20 years with that goal in mind," she says of the clinic's demise. "So when they did close, it was euphoric. And then you think, well, what do I do now?"

It's not that she's not keeping busy. An orthopedic nurse, she still works at a hospital once a week. Between that, her grandchildren, her evangelism on Texas Tech's campus, her Tuesdays passing out fliers on a Lubbock street corner, there's plenty to do.

But it's not the same as her mission outside that clinic, where she says she peacefully prayed for so many years.

She didn't always play by the rules, though, and admits, "I've crossed the line from time to time" -- meaning, she says, the property line.

She joined hands with Operation Rescue in Wichita, Kansas, where Dr. George Tiller -- later shot dead while in church -- was performing second trimester abortions. She helped block doors and says she's been arrested about a dozen times.

From her large white Chevy van in her garage, she offers a brochure and hands over a tiny rubber baby, saying it represents what a baby looks like at 10 weeks in the womb. Leaning against the cargo van's inside wall: an oversized sign, featuring a gruesome image of an aborted fetus.

A place next door

Half of all pregnancies in the United States are unintentional, according to a report in the American Journal of Public Health. And of those unplanned pregnancies, four out of 10 end in abortion.

"Everyone knows someone who's had one, whether they know it or not," says Nan Little Kirkpatrick, the executive director of the Texas Equal Access Fund , which helps women pay for abortions.

While there's no place in Lubbock to get an abortion these days, there are still plenty of places and groups dedicated to talking women out of abortions.

The Nurturing Center , which advertises pregnancy support services and free sonograms, opened next to the now-shuttered abortion clinic by design. On top of ultrasounds, the center offers peer counseling, baby items, referrals to adoption agencies, limited financial assistance -- and lots and lots of warnings about abortions.

"We believe in the sanctity of all life," explains Lawrence D'Souza, the 73-year-old executive director. "Cradle to grave and womb to tomb."

His eyes tear up when he wonders how many scientists have died because they weren't allowed to be born. He reads aloud from a list of scenarios given to women who come to the clinic.

"It's the year 1955, a lady is pregnant with a baby out of wedlock, her family would disown her and so will her community. Should she abort?"

He looks up, to make sure I'm listening, before he reads on: "You would have killed Steve Jobs, the founder of Apple, and nobody would have an iPhone."

The idea to open his center at this location came to him during a clinic protest years ago, after he saw abortion seekers mistakenly walk toward the entry of what was then a closed-down dental clinic. If D'Souza, then a steel company controller, set up shop in that old clinic and put up a sign in lights, there was no telling how many lives he could save.

Sometimes, even though the abortion clinic has been closed for more than two years, women still show up at his center next door thinking they're at Planned Parenthood.

"Women are choosing life maybe because they have no other option," says Elizabeth Trevino, the center's director of client services.

She wears a purple T-shirt emblazoned with a cross and a reference to scripture. When she used to protest outside the clinic, she says she preferred to show love rather than scare off women. She passed out rosaries, baby booties and onesies.

She beams after introducing two Texas Tech activists who are involved with the student-led organization Raiders Defending Life. For two years in a row, their school has been named the most politically active campus in the state at a Texas Right to Life student conference.

Trevino describes the information she shares with women about the dangers of abortion. They're the very claims medical professionals dispute and include risks of severe psychological trauma.

"I have yet to meet a woman who has not regretted her abortion," she says.

That means Trevino hasn't met Anne, a Lubbock-area woman who was years beyond middle-of-the-night feedings when she found herself pregnant. A married professional in her late 40s and already the mother of three, including a teenager, this was a life twist she didn't see coming -- and didn't think was possible.

The decision to have an abortion was easy for her and her husband. Never mind that they didn't want more kids, the thought of carrying a baby to term in her body, at this age, felt dangerous.

She was lucky and had the resources to travel. Her husband was able to watch the kids. She could reschedule some meetings and didn't have to craft excuses for a boss or risk losing pay. She could afford to fly to Denver and not waste a day driving hundreds of miles. She was able to foot a hotel bill.

The procedure the next morning took minutes and, she says, felt no different than a pap smear. But the $1,500 journey, which could have been a lunch-break appointment had Lubbock still had a clinic, felt at best ridiculous and at worst like a violation.

"It bothered me so much after I got back. This could have happened to someone else who doesn't have the means I have," says Anne, who asked that I not use her real name. "This is a real issue affecting real women, not just teenagers acting irresponsibly."

A Texas education

Here in this abortion desert, though, it seems there's more than a lack of clinics. There's also a scarcity of knowledge -- the very kind needed to act responsibly.

The Lubbock area is home to a number of colleges, including Lubbock Christian University, Wayland Baptist University and South Plains College. The largest, by far, is Texas Tech University, home of the Red Raiders.

A group of Texas Tech undergrads, hailing from different parts of the state, tell me about the abstinence-only assemblies they were required to attend in public school and the pledges they felt pressured to sign at 13.

"I signed because I wanted to fit in," says Catherine Ragsdale, 20, an officer in the school's Feminist Majority Leadership Alliance. "I didn't know what sex was."

Another student, who learned she was pregnant over winter break, paints the picture of how Texas' anti-abortion culture colored her reaction. She didn't know who she could talk to at school and worried about being judged for scheduling an abortion (which she ended up canceling after she miscarried). One of her best friends had already dropped out of college to have her own baby. Everyone had tried to be happy: "Congrats!" they said. What would they now think of her?

There was no mention of birth control in their Texas schools, or at least there wasn't supposed to be. One student sang the praises of a teacher who broke the law in seventh grade to tell students about safe sex. Health classes generally amounted to being bombarded with horrifying photos of STDs.

It's no wonder, these young women say, that so many of their peers are clueless -- and that "Raider Rash," the school's signature sexually transmitted infection, is so widespread it has a name among students there.

Faculty in the women's studies department offer additional commentary.

Sara White teaches an introduction to women's studies course, which draws 40 students, equal parts men and women. When she asks students to list the forms of birth control they know about, she says, 9 out of 10 can only come up with abstinence and condoms.

She talks about the young man who said he drank bleach believing it would keep him from impregnating a woman. One student who got pregnant wrote an email to White in a panic: "I didn't think his penis was big enough," as if size was linked to fertility. Other women have admitted douching with Mountain Dew to keep from conceiving.

"They say it's something about carbonation," a student nearby explains.

One young woman told her classmates to set a timer when having sex. She explained that guys only last seven minutes, so if you stop before then you're fine.

"This method was flawed, though," White says. "The student had a child."

White shows them what she calls "the birth control website." It's just the Planned Parenthood site , although she doesn't say the name out loud.

In it for the long haul

Outside a Dallas clinic, one of two in the city, the regular protesters assemble and scream. One protester arrives lugging a huge crucifix. Beside her are two small children.

A clinic staffer rushing inside yells back with a broad smile, "I love my job! Free IUDs!"

Since HB2 forced the closure of abortion clinics across Texas, this Dallas facility has nearly doubled in capacity. For a time, the waiting area was standing-room only. The wait for an appointment jumped from five days to about 20. The clinic had to acquire adjacent space, "a hemorrhoid center of all things," one physician says.

The clinic sees about twice as many patients as before HB2; about 200 come through each week. Patients arrive from all over North Texas as well as Oklahoma, Louisiana and Arkansas.

OBGYNs in private practice in Texas may perform abortions on occasion, but they certainly don't advertise this, says Heather Busby, the executive director of NARAL Pro-Choice Texas . And if hospitals do elective abortions, they risk losing public and private funding. That makes clinics the overwhelming go-to place, which means women of all backgrounds, ages, races and socioeconomic status walk through these doors.

Four physicians work here, some more days than others. Additional doctors are expected to pitch in soon.

One doctor, who insists on not being identified, keeps what she does quiet for her and her family's protection. She doesn't touch social media and often wears sunglasses, even when there is no sun.

When abortion providers in Texas meet with a new patient, they are legally required to read off a list of risks -- a list the doctor calls "ridiculous." Among the warnings: Abortion may cause breast cancer and infertility.

The doctor says she explains to patients that while she has to say these things, science doesn't back up these statements. Yes, women who carry a baby to term are less likely to get breast cancer, but abortions do not cause breast cancer. And there's no evidence linking infertility to uncomplicated abortions, she says.

Nearly 90% of abortions happen within the first term of pregnancy, when there's a less than 0.05% risk of major complications, according to the American Journal of Public Health . In fact, "the risk of death associated with abortion is about one-tenth that associated with childbirth," the Guttmacher Institute reports.

"It's really frustrating and tiresome to explain this to people over and over again," the doctor says. "They've already gone through so much to get here."

She remembers the young college woman from Lubbock who took a bus for eight hours by herself to get here. She'd been afraid to visit a crisis pregnancy center in Lubbock like the Nurturing Center for fear she'd be judged and shamed for wanting an abortion. The doctor began the exam, only to find that the student had a growing ectopic, or tubal, pregnancy -- a condition that can be life threatening.

"It was extremely dangerous. It could have burst on her bus ride," the doctor says. "She literally could have died."

She told the young woman that she would need to go to the hospital immediately and would likely need surgery. The patient, who was in Dallas all alone and scared, insisted that she needed to first go to the bus station to change her ticket, or else she'd lose her fare back to school.

"My heart just sank," the doctor says.

Another doctor, who also won't be named, walks in mocking what she's wearing. She's in a whole surgical getup -- scrubs, a gown, a bonnet, her booties had just been pulled off -- new requirements since the passage of HB2.

The Texas abortion law says physicians must have hospital admitting privileges and clinics must meet the standards of ambulatory surgical centers, or ASCs.

This language may not sound like a big deal, but these are the matters that will be taken up in front of the nation's highest court on Wednesday.

Texas abortion clinics like this one face new restrictions under a law being challenged at the Supreme Court.

Hospitals that don't provide abortions themselves and are state-funded, faith-based or otherwise politically hogtied won't give admitting privileges to an abortion provider.

Then there are the standards of ASCs -- which include building codes like specified door heights, room sizes and hallway widths to accommodate gurneys abortion clinics don't use -- which amount to construction costs most facilities can't swing.

If the U.S. Supreme Court upholds this Texas law, more clinics may close, and not just in Texas. Some states already have similar laws in place; others are watching with their own versions poised and ready to drop.

Another ASC standard is what has this doctor dressed as if she's about to perform heart surgery.

All this for a procedure she usually completes in about five minutes. Not because she rushes, she says, but because she's good and the procedure is simple.

This doctor flies in once a week from New Mexico to work in this Dallas clinic. She hates that she, too, hides who she is and what she does, but in today's climate she feels she has no choice.

She also remembers a woman who'd traveled by bus from afar. She arrived amid heavy rains. A power outage had closed the clinic. Unable to afford a hotel room, the woman roamed the streets over the weekend and spent her nights in a round-the-clock laundromat.

When the clinic finally reopened and she got in, she was required by Texas law to wait another 24 hours after her sonogram before having one of the doctor's five-minute abortions. The clinic got her a hotel room so she could at least clean up, sleep and stay warm.

Both these doctors were trained in other fields -- one as a family physician, the other as an OBGYN -- before completing fellowships in family planning.

For 43 years, since the passage of Roe v. Wade, women have been entitled to abortions under the law in this country. And no matter the challenges, these doctors insist they're in it for the long haul.

There's still plenty of misinformation in their way, however.

After the passage of HB2, callers to a fund that helps cover abortion costs proved this. They were confused and especially scared, the fund's director tells me. They wanted to know if they'd be arrested for getting an abortion.

So the fund changed its outgoing voice mail message to remind women: "Abortion is still legal in Texas."