This thread convinced me to look this up and apparently this site called "Cambridge Bitcoin Electricity Consumption Index" [0] that's continually tracking mining per IP address [1] to figure out where mining is happening.
Not sure how accurate it is, but apparently Texas is 11.22% of America's 37.84% hash rate share, so that works out to about 4% total.
[1]: From the site: "We have partnered with several Bitcoin mining pools to collect geolocational mining facility data in a non-obtrusive and privacy-preserving manner. This geolocational data is based on IP addresses of mining facility operators (‘hashers’) that connect to the servers of mining pools."
