After over a year of secret construction, Planned Parenthood announced its newest abortion facility on Wednesday: an 18,000-square-foot mega-clinic in southern Illinois. The new location is just 13 miles away from Missouri's last remaining abortion clinic, a facility in St. Louis fighting to keep its license.

Since August 2018, Planned Parenthood has used a shell company to construct the facility, leaving no public trace that the former medical office would become one of the largest abortion clinics in the country. CBS News first visited the site in August, while it was still being built.

Colleen McNicholas, the chief medical officer of Planned Parenthood of the St. Louis Region and Southwest Missouri, said the facility was built in secret to avoid protesters and delays. Other Planned Parenthood projects had run into problems once the public realized the construction was for an abortion provider. In one instance, a communications company had refused to install telephone and data lines; in another, a cabinet maker never delivered an order, McNicholas said. In Birmingham, Alabama, protesters targeted Planned Parenthood's suppliers, flooding their social media accounts with fake negative reviews.

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"We were really intentional and thoughtful about making sure that we were able to complete this project as expeditiously as possible because we saw the writing on the wall — patients need better access, so we wanted to get it open as quickly as we could," McNicholas said during an interview with CBS News.

Colleen McNicholas, left, speaks with CBS News' Kate Smith. CBS News

Planned Parenthood expects the facility to begin taking patients later this month. In the meantime, the organization's St. Louis location said it planned to double its clinic escort staff on Wednesday in anticipation of increased protests.

With a newly conservative Supreme Court, access to abortion has come under fire across the South and Midwest, where state lawmakers have raced to pass laws that ban the procedure in hopes of overturning Roe v. Wade, the 1973 Supreme Court case that effectively legalized the procedure.

So far this year, state politicians have introduced 300 bills restricting access to abortion, according to data compiled by the Guttmacher Institute, a reproductive health research organization. Twelve states have passed abortion bans, none of which are currently in effect.

But nowhere is access to abortion less secure than Missouri.

Since 2018, a lone Planned Parenthood has been the state's only legal abortion clinic, pushing some women to spend hours crossing the state to obtain the procedure. In May, that clinic was nearly forced to stop providing abortions when the state's health department refused to renew its license, a story first reported by CBS News. For months, a string of preliminary injunctions has allowed the clinic to continue operating.

Besides having just one clinic in their state, Missouri women face some of the country's most restrictive laws when seeking an abortion. Prior to receiving an abortion, patients are required to undergo state-mandated counseling where they receive anti-abortion literature. After that, they're forced to wait at least 72 hours before they can have their abortion.

In Illinois, lawmakers have gone in the other direction, expanding abortion access and loosening restrictions. Earlier this year, lawmakers in Springfield passed the "Reproductive Health Act," legislation that establishes access to abortion as a fundamental right.

Women from across the Midwest seeking abortions have flocked to Illinois, turning it into what Mary Kate Knorr, the executive director of Illinois Right to Life, an anti-abortion access group, calls "the abortion capital of the Midwest."

"It's a travesty that this is happening," Knorr said in an interview with CBS News. "It's a travesty that women come here to get an abortion."

Since 2017, the number of women crossing the border into Illinois for an abortion has doubled, according to data compiled by the Associated Press.

Providers near the border have seen those increases firsthand. At The Hope Clinic, a Granite City, Illinois-based abortion provider about 10-miles away from St. Louis, about 55% of patients seeking abortions are from Missouri, according to the clinic's deputy director Alison Dreith. On a recent day at Planned Parenthood's existing facility in Belleville, Illinois, just two miles from Planned Parenthood's new facility, every patient was from Missouri, something that Jessica Herbert, a provider at the clinic, said is typical.

"It's because they can't access basic healthcare in Missouri," Herbert said in an interview with CBS News. "There is a lot of hoops they have to jump through. It's fiscally easier for them to come here."

A tiny clinic nestled in the corner of a small strip mall, Herbert's office has seen a 300% increase in patients since 2016, an influx the facility isn't built to handle. Herbert says the office is at "max capacity," and patients seeking an appointment can wait up to six weeks to be seen. For some, that wait time can push women outside the legal timeline for certain abortion methods.

The small Planned Parenthood used to provide services beyond just abortion, like birth control and cancer screenings. But in 2018, Missouri's abortion clinics stopped offering medication abortion — commonly known as a pill abortion — and referred patients seeking that method to the Belleville location. After that, the Illinois Planned Parenthood became flooded with abortion patients from Missouri.

"We try to balance our schedule as best as we can but we are only a couple of people," Herbert said. "We are kind of a Cracker Jack box health center. You don't walk next to someone without brushing their shoulder, so absolutely we stretch our limits to the very best we can, but there's only so much we can do and at the end of the day."

The influx left little room for those seeking services outside of abortion care, Herbert said. With the opening of the mega-clinic nearby, they'll be able to expand those services, said McNicholas, who added that Planned Parenthood was expanding its staffing in the region to handle both family planning and abortion services. The new facility will roughly double the existing clinic's capacity, with the ability to serve up to 11,000 patients a year, said a spokesperson for Planned Parenthood.

Even though the new facility could absorb all of St. Louis's patients if the clinic has to stop performing abortions, McNicholas said the new clinic doesn't mean they're giving up on Missouri.

"Our supporters, our patients, the board, everyone is so committed to the mission of being present in Missouri and taking the responsibility to provide access to abortion for Missourians in the place they live," she said. "Although I am confident it will be a fight, we will continue to show up to that fight."