Green Timbers Park is wide open and has lots of trails. There is a parking lot on 100th & 140th where you can access the trails.
Each trail has a name and the trails seem easy to navigate your way around to find your way back to the parking lot. It is very peaceful and seems to be lots of people walking around in the trails. Combined trails can get you up to 5 km of exercise. They are mostly flat, gravel trails. There are picnic tables, benches and a beautiful lake stocked with fish. If you are nervous going in the trails alone or with your dog, you could walk around the lake area a few times, which is very open. It is well maintained and beautiful in the middle of a busy city. Happy Trails!