The Saturday Aug 13, 2016 Dragons Den Half Marathon in San Antonio, TX is a USATF sanctioned 2 loop course. The course is a mixture of asphalt, concrete, dirt roads and technical trails. With this in mind, along with the heat, I wouldn't consider the course walker friendly, even though the event allows 4 hours. With the technical trails added in there, the course is not going to be comparable to a road half marathon. Those that can withstand the heat and trails, are in for some great post race goodies, .... beer and turkey legs! Additionally, the first 100 to register receive a technical running tank, and all finishers receive a regular finisher shirt and a blazin' lookin' medal. Visit the Texas half marathons page and scroll to August half marathons for a direct link to the event.
Texas Half Marathons 2016 page