My favorite running and biking park. Lots of trail options allow you to vary the runs. I ran yesterday over lunch and didn't run into a single person. That doesn't happen often. Weekend mornings are the busiest.
This is a loop course and you should be able to get in anywhere from 3-6 miles depending upon your route.
If you're running/walking make sure to go in the opposite direction of the bikers and give them the right-of-way.
Also, please, please, please keep your dog on a leash and pick up their poop. As a dog owner, it ticks me off to see people willfully ignoring basic rules of courtesy.