The only hills I see are on the sidewalks. There are a couple around George Bush Park.Mountain biking in Houston sucks, but I still do it. Tons of pedaling & no good downhill reward. We have pine roots in spades, though, if roots are your thing.
I drag my bike up to Huntsville State Park and the Sam Houston Natl Forest pretty often for a change of pace. Still no good downhills. I need to venture to Austin more. Anyone ever ridden Spider Mountain?
And a picture of my favorite current bike.