Because many of you asked how we are getting the mileage with three of us, here's an attempt to explain how we're doing it:
1 We drive to where we stopped walking the previous day and drop off Walker#1.
2. Then we drive 8 miles down the road, and Walker# 2 gets out and starts walking while the Driver waits for Walker # 1 to get to the car.
3. Driver and Walker 1 drive down to find Walker 2. At this point we have walked about 16 miles
4. The Driver gets out and walks 4 miles while Walker 1 drives 8 miles and drops off Walker 2. Walker 1 then drives back 4 miles to wait for Driver. When she arrives, Walker 1 walks the 4 remaining miles and Driver drives to where Walker 2 was dropped.
5. Driver and Walker 1 drive down to find Walker 2.
So Walker 1 does about 12 miles, Walker 2 at least 15 and Driver around 4 miles
If you're still confused, try mapping it out on a table using utensils or something to represent the three of us.