Ok, fresh set of eyes here, approaching this as a "new" visitor to Texas. Taking a look at the Texas category page, I find it very difficult to use in its current from. First, there is a lot of text at the top, most of which would be better on either the Texas project page or a Texas resource page. I have to scroll down a lot before I get to the subcategories. I find that unhelpful.
Due to the large number of counties in Texas, it makes it difficult to find other Texas subcategories that are not county-related. If county categories were moved to their own subcategory, it would make it MUCH easier for me to find other Texas-related categories. Right now, these other topics are buried within the long list of counties. Since the purpose of categories is to help people find groupings of interest and profiles related to those groupings, a county subcategory would aide in that.
And it would be awesome to find those other categories under their appropriate alphabetical letter. If I was looking for Artists from Texas, I would go looking for them under A, not under T, especially since I am already in the Texas main category.
My $.02