"Currently exists: No" in Texas Almanac [1]. Do note, however, that this seems to refer to its existence as an *independent* entity, not necessarily as a neighborhood.

[1] "Zummo", in Texas Almanac, Texas State Historical Association, accessed 27 Oct. 2025, <https://www.texasalmanac.com/places/zummo>, archived from the original on 23 Apr. 2024, <https://web.archive.org/web/20240423120324/https://www.texasalmanac.com/places/zummo>.