Clark's Creek Greenway runs in the University Area and connects to several neighborhoods near Mallard Creek Rd/Prosperity Church Rd/West WT Harris. This greenway is all paved asphalt and starting from Mallard Creek Elementary School the portion of the Greenway is about 4 miles to where it dumps you out into a cul-de-sac of a neighborhood. Combined with Mallard Creek Greenway and the unpaved section (1.9miles) in University Research Park you can make a 12 mile run [out and back] or bike ride.
If you start at the elementary school there's a big hill to get down to the creek area, and it's all uphill from there (slight grade)... the good thing about starting at the school is you park your car and go out.... when you turn around... it's downhill from there (except getting back to the parking lot).