From the UIL Website:

https://www.uiltexas.org/music/state-mariachi-festival

"At a site to be determined."

Given that it has to happen AFTER UIL Region S&E, it may be a bit before we know. It wouldn't surprise me to see it be a fully virtual contest.

It's hard to pick a facility when they don't know how many groups will qualify - or even participate at the region level. Region marching band was down about 50% from last year. I bet S&E will be even lower.