Need help figuring out how to log certian exercises

Hello, I have been walking 4 miles a day. I have been doing that in an hour so I have been logging that as walking 4mph for 60 minutes. What I was wondering is that I don't walk on a treadmill, I live in the country so I walk on our county road. It has a lot of inclines and hills. Should I be logging this different? I could not find a way to log walking on a incline. Thanks for the help.