Question about a low level route in southeast Williamson County. I see T-6's and T-1's flying over my property. (NO COMPLAINTS ! - I'm an ex RF-101 driver and understand the need for LL training.) The route obviously crosses over US79 between Taylor and Thrall, proceeds south and crosses US290 between Butler and McDade. It is not shown on the San Antonio Sectional. Again, I am not making a complaint; I'm just curious as to where the route enters and exits and who flies it. Over the years, it's been flown by C-130's and T-37's. Thanks in advance for any info.