MISSION, Texas (AP) — An idled Border Patrol bus sat empty this week, on standby for any migrants surrendering near the southern tip of Texas.

Agents in two speedboats zipped past pockets of sandy shores, known landing spots for people entering the U.S. illegally from Mexico on inner tubes but saw nothing suspicious.

Once busy river landings near the Texas border city of Mission were barren of the migrants who previously crossed there, though the river bank was littered with clothes, plastic bracelets issued by smugglers and a teddy bear on an unusually cold Thursday morning.

Arrests for illegal crossings have fallen dramatically from an all-time monthly high of 250,000 in December 2023, perhaps most strikingly in the Rio Grande Valley, the epicenter for migrant arrivals from 2013 to 2022.

Associated Press journalists accompanying Border Patrol agents in an SUV and on speedboats that traversed 30 miles along the Rio Grande Valley and river for five hours Thursday didn’t encounter a single migrant.

Arrests, already at their lowest levels since 2019 when President Donald Trump took office on Jan. 20, have fallen sharply in recent weeks. Border Patrol Chief Michael Banks said Friday they are currently about 350 a day, down from more than 1,500 daily in December, the last month of published data.

Border Patrol agents in the Rio Grande Valley, home to about 1.4 million people, have been making about 50 arrests a day, down from a daily average of 325 in December and nearly 3,000 on the busiest days of 2021.

Despite the relative calm, Trump declared a national emergency at the border on his first day in office.

In an immigration policy memo, as she took office last week, Attorney General Pam Bondi wrote: “Unlawful border crossings and illegal migration into the United States have reached record levels, resulting in a substantial and unacceptable threat to our national security and public safety.”

Overnight Thursday, there were arrests along the Rio Grande, as well as a shooting Wednesday. The Border Patrol said an agent fired at someone in a suspected smuggling incident in the town of Boca Chica, wounding one suspect.

But migrants were nowhere to be found along the river by Thursday morning in former hot spots like Mission, a city of 87,000 where as recently as December asylum-seekers waited in open fields near a busy international bridge for agents to pick them up, or in many other spots along the winding river lined by thick, giant cane.

Heightened enforcement by Mexican authorities within their own borders and severe U.S. asylum restrictions contributed to sharp declines in illegal crossings before Trump took office.

In recent years, the Texas National Guard and state police have become a major presence under Gov. Greg Abbott’s “Operation Lone Star,” a multibillion-dollar border crackdown. U.S. Customs and Border Protection recently agreed to let the Texas Guard arrest and detain people for illegal crossings, which had been the sole domain of the federal government.

On Thursday, 300 Texas Guard members were deputized to conduct immigration arrests alongside Border Patrol agents and enlarge their show of force along the border.