EL PASO, Texas – Kari Lenander runs migrant shelters in west Texas and New Mexico where every green cot has regularly been filled for years.

Now most of the beds are empty.

Along the U.S.-Mexico border, migrant apprehensions plunged in July from a year ago, to the lowest level of the Biden era, according to U.S. Customs and Border Protection statistics provided to USA TODAY.

Migrant crossings have declined every month for the past five months. The results mark a rare victory on one of the Biden administration's toughest political battlefronts, as Vice President Kamala Harris prepares for next week’s Democratic National Convention. CBP is expected to publicly release the new border data Friday.

"The numbers have indeed decreased and have decreased significantly," Homeland Security Sec. Alejandro Mayorkas told USA TODAY. "The reason for it is not singular. It is a number of different measures that we and others have taken."

Those measures include the creation of new, lawful pathways for migrants to enter the United States in an orderly way, Mayorkas said; consequences for crossing illegally; tougher restrictions on asylum; and hard-won diplomacy with Mexico, Guatemala, Panama and Colombia as those countries boost their own border enforcement and humanitarian relief programs.

Shifts in U.S. border policy often generate temporary dips in border crossings as migrants wait and see how policies will affect them and smugglers evaluate how to poke holes in the system. Executive orders and other administrative changes can face legal challenges that soften their bite. And Mexico has rarely kept a crackdown going as long as it has this year.

Lenander knows the dips don't usually last.

Her shelter in El Paso is clean and bright. The white walls are decorated with rainbow colors and the flags of many countries. The medical clinic inside is equipped, staffed and waiting. A laundry room with industrial washers and dryers is silent. She switches on the lights to an empty classroom used for immigration orientations.

"It's eerie," she said, of the sudden decline in migration.

The problems that drive people to flee their homeland haven't changed. So where did all the migrants go?

Migration numbers tell a new story

Republicans have spent the years of the Biden administration attacking its "open border" policies. The numbers didn't lie. Migrant encounters broke historical records each of the past three years, topping 2.5 million last year.

At the Republican National Convention in July, Texas Gov. Greg Abbott, one of the party's fiercest immigration hawks, promised to keep sending "migrant buses" to "sanctuary cities" – including Chicago – until the Biden-Harris administration secured the border. The crowd cheered.

Republicans haven't shifted their message, but the numbers are telling a new story.

As Harris and Democrats head to Chicago for their convention this weekend, there are no "migrant buses" left, say migrant shelter directors in Texas. The governor's press secretary attributed the decline in crossings to the state's own border security operation and said buses "continue to stage" along the southern border.

"Fewer illegal crossings into Texas means there are fewer buses departing for sanctuary cities," said spokesman Andrew Mahaleris.

But U.S. Customs and Border Protection data showed migrant encounters declined in July, compared with June, in all nine Border Patrol sectors at the Southwest border, from Texas to California.

CBP reported 56,408 migrant encounters between ports of entry in July, down 57% from 132,642 the same month a year ago and down 32% from June.

CBP reported declines across all demographics – single adults, family units, unaccompanied minors – at a time when seasonal migration usually surges.

The number of migrant encounters at ports of entry, via CBP One appointments, also declined in July, year over year: to roughly 38,000 from more than 44,000 in the same month a year ago.

Lenander said her shelter continues to receive migrants, about 100 per day, but the vast majority crossed using the CBP One app. They aren't eligible to ride the Texas "migrant buses," only those who crossed unlawfully, between ports of entry, can board.

El Paso was the last of the governor's bus staging locations, Lenander said. The state staged its final bus, for now, last week.

"The buses have stopped," she said. "Not because Abbott wanted them to stop but because there weren't any people."

Efforts to curb illegal immigration at the border

Across the border from El Paso in Ciudad Juárez, Mexico, a heavy rain left the Rio Grande channel filled with water on a recent morning. A pair of children's sandals lay abandoned on the riverbank alongside tubes of toothpaste, an empty can of tuna, trash left by migrants who came before.

There were hundreds of people and families here earlier this year, waiting for a chance to cut through the curtains of concertina wire laid by Texas National Guard to turn themselves in to Border Patrol. Now the banks were empty except for a single family huddled in the brush. A woman combed her fingers through a little girl's hair as she slept.

Reducing dangerous crossings between ports of entry has been one of the Biden administration's key goals from the beginning – and the one that has been the hardest to attain.

Early in the administration, Harris famously told migrants, "Do not come," echoing a Border Patrol talking point. In the wake of the COVID-19 pandemic, and the global social and economic upheaval that followed, migrants ignored her message and came to the U.S. border in massive numbers.

Illegal crossings surged to their highest-ever level in 2023, with more than 300,000 irregular crossings in December alone. The White House backed bipartisan negotiations in Congress aimed at a border security deal.

The resulting Senate bill included funds for hundreds of additional Border Patrol agents and detention capacity. It tightened access to the U.S. asylum system and ended the Border Patrol practice of apprehending migrants and releasing them into the U.S. to pursue their claims.

But it failed after former President Donald Trump bashed it as a "highly sophisticated trap for Republicans." That was in February. In May, Democratic lawmakers re-launched the bill and it failed again.

Meanwhile, the Biden administration's talks with Mexico and other countries were starting to result in shared enforcement priorities and relief efforts, slowing the flow migrants through the region. Tens of thousands of people were still bound for the U.S. – but it was becoming harder, and taking longer, to reach the border.

More:The real migrant bus king of North America isn't the Texas governor. It's Mexico's president.

Then, in June, the White House issued an executive order that sharply restricted migrants' ability to claim asylum at the border – essentially closing a path millions of migrants used to enter the United States over the past decade.

The Department of Homeland Security began ramping up deportations and removals from the U.S., too. In July, Mayorkas announced a deal under which the U.S. will pay Panama to deport foreign nationals. The agency also made smaller adjustments, like adding new layers of security to block migrants from making a CBP One appointments from outside Mexico.

The reality is that the decline in unlawful border crossings "has lasted longer than other measures in the past," Mayorkas said.

"The smuggling organizations do pivot according to what we do," he said. "However, in this case, it is really a comprehensive suite of measures. I do think that reality is a reason why this has lasted longer."

Every day, Lenander and other shelter directors receive a notification from Border Patrol's El Paso Sector letting them know how many people will be released and how many people need shelter. It used to be in the hundreds.

Nowadays, it's often single digits, she said. Nine migrants on a recent day, or seven.

Under the wire

As the morning sun broke through what remained of the night's storm clouds, the group huddled on the river bank stood up, stretched and walked over to a place where the concertina wire could be lifted like a blanket.

The little girl, in pink shorts and a white T-shirt, crawled up the dirt bank under the sharp wire coils. Three women followed her, and then a man.

The coils rattled and scraped with a metallic sound, like a slinky clinking down stairs. It took less than 10 minutes for the group to wrest itself from wire. A Texas National Guardsman pulled up in a white, mud-splattered truck and shouted for them to return to Mexico.

Instead, they ran for the U.S. border wall. A few minutes later, a Border Patrol agent arrived. The migrants sat along the fence line, their fate uncertain.

Would they be deported to their country of origin, sent back to Mexico or released to Lenander's or another shelter?

Without a CBP One appointment, they'd likely be returned.

It's not clear whether the migrants knew about the new rules. Migrants "have a lot of information needs," said Daniel Berlin, International Rescue Committee policy director for protection pathways. "The situation both in Mexico and at the U.S. border is extremely complicated."

"Regardless of what smuggling networks and other channels are saying," he said, "the U.S. border is not open by any stretch. It’s as closed as it has been in a very long time."