Immigration advocates gather like clockwork outside Seattle’s King County International Airport to witness deportation flights and spread word of where they are going and how many people are aboard. Until recently, they could keep track of the flights using publicly accessible websites.

But the monitors and others say airlines are now using dummy call signs for deportation flights and are blocking the planes’ tail numbers from tracking websites, even as the number of deportation flights hits record highs under President Donald Trump. The changes forced them to find other ways to follow the flights, including by sharing information with other groups and using data from an open-source exchange that tracks aircraft transmissions.

Their work helps people locate loved ones who are deported in the absence of information from U.S. Immigration and Customs Enforcement, which rarely discloses flights. News organizations have used such flight tracking in reporting.

Tom Cartwright, a retired J.P. Morgan financial officer turned immigration advocate, tracked 1,214 deportation-related flights in July — the highest level since he started watching in January 2020. About 80% are operated by three airlines: GlobalX, Eastern Air Express and Avelo Airlines. They carry immigrants to other airports to be transferred to overseas flights or take them across the border, mostly to Central American countries and Mexico.

Cartwright tracked 5,962 flights from the start of Trump’s second term through July, a 41% increase from 1,721 over the same period in 2024. Those figures including information from major deportation airports but not smaller ones like King County International Airport, also known as Boeing Field. Cartwright’s figures include 68 military deportation flights since January — 18 in July alone. Most have gone to Guantánamo Bay, Cuba.

The work became so demanding that Cartwright, 71, and his group, Witness at the Border, turned over the job this month to Human Rights First, which dubbed its project “ICE Flight Monitor.”

“His work brings essential transparency to U.S. government actions impacting thousands of lives and stands as a powerful example of citizen-driven accountability in defense of human rights and democracy,” Uzrz Zeya, Human Rights First’s chief executive officer, said.

The airlines did not respond to multiple email requests for comment. ICE is part of the Department of Homeland Security, which would not confirm any security measures it has taken.

La Resistencia, a Seattle-area nonprofit immigration rights group, has monitored 59 flights at Boeing Field and five at the Yakima airport in 2025, surpassing its 2024 total of 42.

Not all are deportation flights. Many are headed to or from immigration detention centers or to airports near the border. La Resistencia counted 1,023 immigrants brought in to go to the ICE detention center in Tacoma, Washington, and 2,279 flown out, often to states on the U.S.-Mexico border.