Texas has multiple places called "Hell's Gates" but we have at least two that are frequently mentioned.
First up is "Hells Gates" in Lubbock, Texas. The place is near an old train trestle and is generally known as one of those places that teenagers dare each other to check out, and/or a place to go party. The place has become such a local legend, even I wrote up a little fan fiction about the location. This was necessary in my opinion, because there's no real reason for people to think the area is haunted, meaning I can't find where any actual tragedies or ghost team-building exercises happened there.
The other, most popular "Hell's Gate" would be adjacent/part of Possum Kingdom Lake. This is the one that people are most likely familiar with, but it seems that a LOT of lakes in Texas have a place called "Hell's Gate", including Lake Travis, Lake Amistad, Lake Granbury, Eagle Mountain Lake, near the Buchanan Dam in Del Rio, Canyon Lake, Median Lake, and more. Most describe a narrow passage of water.
I have to admit that I am ultimately disappointed by this news. I was hoping for more spooky places named Hell's Gates. I guess somewhere along the way some water-bound cowboy went around naming every rough patch of water "Hell's Gate".
All of this would be much more interesting if we had some folks in weird robes chanting at a fire in the middle of some drawings done with salt, but sometimes we just don't get to have fun things. I guess if we're looking for actual portals to hell, we'll have to go to our local D.M.V.