Kitty-litter grade and smaller gravel with some ruts and washboards here and there - the biggest danger is the deeper sections of gravel that exist and act like sandtraps- gotta keep on your toes and those pressures low for best stability. Also, best to bunnyhop those bridge transitions as they're about 2" or so. This is an equestrian and hiking trail too, so be aware of the piles of horse exhaust you definitely do now want to be picking out of your tires. But it is a BEAUTIFUL stretch of reclaimed railway with a nice canopy of trees to mitigate the wind or any direct sun. Also at the end, it dumps you right into the state park and a nice park store stocked with the #1 Texas summer cycling fuel: ice cream.