Children were discharged Saturday from Joint Base San Antonio-Lackland in Texas, and the shelter closed earlier this week, said Krista Piferrer, a spokeswoman for according to BCFS, a nonprofit group contracted to run the shelter.
The shelter at Fort Sill in southwest Oklahoma closed Aug. 6, said Kenneth Wolfe, the spokesman for the U.S. Department of Health and Human Services' Administration for Children and Families. The shelter at Naval Base Ventura County in California shut down Aug. 7, Wolfe told the Ventura County Star.
The shelters could be reopened if border crossings spike again, Wolfe previously said.
About 7,700 children were housed at the bases since shelters opened in May and early June. The average stay was 35 days.
Last week, government officials estimated that closing all three shelters would take between two to eight weeks.
From October to June, more than 57,000 unaccompanied children, mostly from Honduras, Guatemala and El Salvador, have been caught illegally crossing the U.S.-Mexico border.
By law, unaccompanied child immigrants from countries that don't border the United States must be handed over to the Department of Health and Human Services within 72 hours of being detained. The government is responsible for caring for the children until they are united with a relative or sponsor in the U.S. while waiting for immigration court hearings to proceed.
The number of unaccompanied youth immigrants crossing the border alone has declined from about 2,000 per week in June to 500 per week in mid-July, according to the U.S. Department of Homeland Security. Federal officials cautioned that high summer temperatures typically result in a decrease in border crossings.
Up to 90,000 child immigrants could cross the border by the end of September, federal officials have said.