For decades, the Pregnancy Control Clinic, tucked inside a squat, beige building around the corner from a bowling alley, handled most of the abortions on Guam, a tiny U.S. territory 1,600 miles south of Japan.

But the doctor who ran it retired seven years ago, and the clinic now appears abandoned. An old medical exam table stands near a vanity with a dislodged faucet, and a letter from Dr. Edmund A. Griley is taped to the front door: “My last day of seeing patients is November 18, 2016,” he wrote. “I recommend that you begin looking for a new physician as soon as possible.”

Dr. Griley has since died, and his deserted clinic is a dusty snapshot of Guam’s past — and some say, its future.

Though abortion is legal in Guam up to 13 weeks of pregnancy, and later in certain cases, the last doctor who performed abortions left Guam in 2018. The closest abortion clinic on American soil is in Hawaii, an eight-hour flight away. And a pending court case could soon cut off access to abortion pills, the last way for most women on Guam to get legal abortions.

As anti-abortion activists around the country capitalize on momentum from the overturning of Roe v. Wade, Guam, a speck of land in the Pacific, stands out.

Forces on both sides of the abortion debate say that the island of 154,000 people is on track to become the purest example of what life would be like under a near-total ban. More than a dozen states have banned most abortions, forcing women there who seek to terminate pregnancies to travel elsewhere, sometimes at great cost and risk to their health. But none is as isolated as Guam.

“Guam is a litmus test,” said the territory’s attorney general, Douglas Moylan, a Republican who opposes abortion. “If anti-abortion forces were to succeed anywhere in the United States, I would say Guam would be one of them.”

There are two doctors who are licensed in Guam and willing to provide abortions, and both are based in Hawaii, where they can see patients through video calls and prescribe abortion pills. That could change if the Ninth Circuit Court of Appeals reinstates a territorial law that would require women to see a doctor in person in order to obtain pills.

A streak of anti-abortion sentiment runs through Guam, and there are other attempts to further restrict the procedure. Mr. Moylan, the attorney general, is fighting in federal court to try to revive a 1990 law that banned nearly all abortions but was blocked by a federal judge. In the meantime, the legislature passed a bill last year that would prohibit most abortions after six weeks of pregnancy. It was vetoed by Gov. Lou Leon Guerrero, a Democrat, a nurse and the island’s first female governor.

She recalled that as a student in California before the Roe v. Wade decision, she cared for women who were “hemorrhaging because either they self-aborted or they went to underground abortion clinics and they didn’t do it right.”

As the head of the Guam Nurses Association, Ms. Leon Guerrero testified in opposition to the 1990 ban, which would have made it a crime to perform, undergo or seek an abortion, except in some medical emergencies, or to encourage women to have abortions. A federal court ruled that the law was unconstitutional and blocked the territorial government from enforcing it, but it remains on the books.

“Everything that’s going around impacts Guam, and our women here, because we’re much more isolated in terms of access to health care,” the governor said.

Guam is so far to the west of the continental United States that its clocks are 15 hours ahead of Eastern Standard Time, in the same time zone as Vladivostok, Russia, and the east coast of Australia. The island promotes itself as “where America’s day begins.”

But though they are American citizens, residents of Guam, who mostly identify ethnically either as Chamorro, the Indigenous people of the Mariana Islands, or as Filipino, cannot vote for president or send voting representatives to Congress.

About one-third of the island is controlled by the Department of Defense, whose footprint is expanding. Though abortions are not available on the island’s military bases except in emergencies, the Pentagon will pay for abortion-related travel for troops serving in places where the procedure is illegal.

Abortion has long been a taboo topic in Pacific island communities; about 80 percent of Guam’s inhabitants are Catholic, reflecting the island’s Spanish colonial past.

Dr. William Freeman, the last doctor who performed abortions on Guam, left the island in 2018. Dr. Freeman, who is now 78 and living in Manila, said that when he first arrived on Guam 39 years ago, the seven doctors who performed abortions often received “phone calls threatening to kill us or blow us up.”

When he retired, a partner who opposed abortion declined to continue that part of their practice. Dr. Freeman suggested having doctors visit Guam for six-week stints to provide the procedure, but “no group was willing to make their clinic available,” he said.

The Guam law that requires women seeking an abortion to receive government-mandated information from a doctor — and only in person — has been blocked by a court order while a legal challenge proceeds. The two Hawaii-based doctors argue in their lawsuit that if the injunction is lifted, it would become practically impossible for them to assist women on Guam through telemedicine.

That would be a victory, as far as the island’s Catholic officials are concerned. In an interview at the chancery of the Archdiocese of Agana, where Pope John Paul II stayed overnight in 1981, Father Romeo Convocar, the apostolic administrator, said that abortion pills obtained by telemedicine is now one of his biggest concerns.

Last summer, anticipating that the Supreme Court would soon reverse the Roe v. Wade decision, the archdiocese distributed a pastoral letter to be read aloud in its two dozen churches: “Hope is rising across our country that the scourge of abortion will be significantly curtailed.”

Catholic officials pushed for the territory to adopt a six-week ban. They resumed conducting a ceremony for the burial of unclaimed fetuses from miscarriages or abortions. They applauded Mr. Moylan’s legal endeavors to reinstate the 1990 abortion ban.

Sharon O’Mallan, chairperson of the Guam Catholic Pro-Life Committee, called the Dobbs decision overturning Roe v. Wade “great — now it turns it over to us, and we now decide what we want as our laws.”

In late April, she and Agnes White, a nurse, pointed to a billboard that they had helped to create: “Healing the pain of abortion — one weekend at a time.”

The goal, they said, was to recruit women who had abortions to attend a confidential counseling retreat sponsored by an international religious group that opposes abortion.

Advocates of abortion rights fear what will happen on Guam — which has high rates of sexual assault and maternal mortality — if access to abortion pills is effectively blocked. The lawsuit filed by the Hawaii doctors, for instance, argues that women on Guam would face heightened medical risks, as well as daunting financial and logistical burdens. (According to census data, the median annual household income, excluding military families, was $58,000 in 2019, or about 20 percent below the national average.)

Famalao’an Rights, a reproductive rights nonprofit founded in 2019,stepped up its organizing in 2022 when the proposed six-week ban was gaining traction. A legislative committee’s 2,200-page report on the bill crackled with anguished emails and handwritten letters from the public, mostly opposing the ban.

Then came the Dobbs decision and its aftermath. “It just felt like we were at the top of the hill, so close to the finish line, and then the finish line moved,” said Kiana Joy Yabut, a leader in the group.

The Dobbs decision was demoralizing for the activists, who are bracing for more anti-abortion bills and preparing to help women obtain abortions, even if it means breaking the law.

“I would gladly go to jail,” Ms. Yabut said.

Women on Guam said they have already been dealing with the difficulty and stigma of abortion for years.

Happy Tingson was working as a hotel housekeeper in 2015, when she became pregnant. She told only two people: her best friend, Rhea Patino, and her boyfriend at the time.

“Not a single smile on his face,” said Ms. Tingson, who was comforted by Ms. Patino and another friend when she became emotional during an interview at her sister’s house. “He was pretty much saying, ‘It’s not the right time for us to have it, we’re not financially stable,’ ” Ms. Tingson said.

Ms. Patino drove Ms. Tingson to the Pregnancy Control Clinic, which has since closed, to receive the procedure, which cost $500 in 2015. “When I finally got it done, I felt kind of broken,” Ms. Tingson said.

She never told her parents, who are now dead, she said. She still hasn’t told her older brother.

Asked if any of her friends had also undergone an abortion, Ms. Patino interrupted: “Me.”

When Ms. Patino, a waitress, became pregnant in the fall of 2020, she and her boyfriend at the time agreed that they could not afford to raise a child.

“I felt helpless,” she said. “Try talking to a doctor, and they’re like, ‘I’m sorry, we don’t support that.’ ”

Ms. Patino, who by then was seven weeks pregnant, decided that the most reliable option was to fly to Florida. Planned Parenthood unexpectedly waived its $500 fee for her.

“They said the fact that you came from Guam, and had to fly out here — it’s so sad, because you have no clinic out there,” Ms. Pitino, now 32, recalled. “That’s so dangerous. How can they do that to you guys?”