Loop 306 is a state loop that runs around most of San Angelo, Texas. One part of the highway is named Houston Harte Expressway, named after the San Angelo-native publishing magnate. The construction of this part of the highway was begun August 10, 2001 and was completed March 22, 2004. TxDOT upgraded portions of Loop 306 to expand it from a two-lane road to a four-lane divided highway. From the US 67/277 interchange, Loop 306 continues as a four-lane divided highway all the way to U.S. 87.