Texas County Flags

I didn't know that counties in Texas had a county flag. Is this flag official? Are there other counties with flags?

Apparently the answer is yes. Here's a site with some shown.

Brazos County Texas Flag

Bosque County Texas Flag

The Brazoria County Flag looks just like the Brazos County flag.  Hmmm.

Brazoria County Texas Flag

Colorado County Texas Flag

Flag of Victoria County Texas