I was thinking the same thing Luke. 1890's Warren ponies are rare birds to boot.
The article claims 1890, but if you look at images of the bridge, such as https://twoworldstreasures.com/10-surprising-things-to-see-a..., it matches ca 1910 trusses like http://bridgehunter.com/tx/ellis/mt-zion-road/ more than an 1890s structure.
here is the bridge thats in the park