Counties with more than 50 undocumented immigrant kids. Click to view interactive version. (Niraj Chokshi/The Washington Post)

UPDATE: An earlier version of the map above omitted certain counties.

Of the tens of thousands of undocumented immigrant children apprehended this year, nearly four in five of those temporarily released have been sent to a small share of counties, according to government data.

A surge early in the summer has died down, with new data released Wednesday showing the number of children caught crossing the border illegally and without parents last month was about a third of what it was just two months earlier. Border Patrol agents apprehended 3,129 children in August, 5,400 in July and more than 10,600 in June. Still, the number of children apprehended so far this fiscal year is 88 percent higher than during the same period last year, according to Customs and Border Protection data.

Once caught, the children are cared for by the government and then released to sponsors — typically family members — as they await immigration proceedings. As the map above shows, sponsors in 126 counties received just under 30,000 of the 37,477 children caught from January through July, according to recent data from the Office of Refugee Resettlement. Harris County, Tex., received the most, with 2,866 children placed with sponsors there. Sponsors in Los Angeles County received 1,993 children. Suffolk County, N.Y., and Miami-Dade County received more than 1,100 children each, while sponsors in Nassau County, N.Y., and Fairfax County, Va., received more than 1,000 each. Sponsors in Prince George’s County, Md., received 960 children.

The influx has spurred local aid groups into action, as our own Pamela Constable noted last week:

Social service and immigrant aid agencies throughout the Washington region have geared up to assist children who have been taken into federal custody while crossing the border and sent to live with their parents or guardians such as aunts or uncles.

A smaller number of youngsters have been placed in shelters or other residential facilities run by religious or private groups. So far, there has been no significant outcry over the arrival of the undocumented children in the Washington region. Some U.S. communities on the Mexican border, however, have erupted in protests and confrontations.

Governors in dozens of states commented on the surge earlier this summer, with several criticizing the administration in letters and statements for what they saw as a lack of communication about the problem and placements. Several officials called on the federal government to help pay the cost of providing services to the undocumented children within their borders. Arizona’s superintendent of schools, for example, recently requested $1 million be paid for the education provided to the immigrant children placed in his state.

An interactive version of the map above can be accessed here.