A massive surge of underage migrants is overwhelming the southern border of the U.S. and Rep. Jim Bridenstine, R-Okla., wanted to see for himself what was going on.

He wasn't happy with what he saw -- or more accurately, what he didn't see. Officials from the Health and Human Services Department wouldn't let him in.

"Yesterday I was denied access to the HHS facility at Ft. Sill, Okla., currently housing up to 1,200 unaccompanied alien children who illegally crossed the southern border into the United States," Bridenstine posted Wednesday on his Facebook page.

"As a Congressman and House Armed Services Committee member, there is no excuse for denying me access to the UAC facility at Ft. Sill.

"What are they trying to hide? Do they not want the children to speak with Members of Congress? As a Navy pilot, I have been involved in operations countering illicit human trafficking. I would like to know to whom these children are being released."

It's the latest example of the secrecy surrounding how the Obama administration is dealing with the more than 50,000 underage migrants who have entered the U.S. illegally so far this year.

The president seems more interested in using them to push for the immigration legislation he wants -- which many Republicans in Congress oppose -- than in stopping the flow. Federal officials have made sure the migrants have access to lawyers who can help them make the case for staying in the U.S., even as members of Congress are being kept away from them.

And the secrecy doesn't just extend to keeping lawmakers out: Fox News reported Wednesday that medical staff at a camp for migrants at Lackland Air Force Base, Texas, were being warned to keep quiet about the threat of an epidemic from contagious diseases being brought into the country or face arrest.