I am not fit enough to climb a local landmark's steep 1.6 mile trail. For now, a friend drops me off at the top of the hill. Resisting gravity provides a good workout, and I am forced to walk the entire course to get a ride home with my friend, who waits at the bottom of the hill.
Walking steep grades works a different set of muscles than treadmill or flat course walking. It also places more stress on the knees. Make sure to wear friction free socks and quality shock absorbing shoes.