I am looking to take my two sons ages 10 and 12 out on Columbia (which I've never been on myself). My biggest concern is my 10 year old. He doesn't have a lot of stamina and only has a Trek MT60 20" bike. I am looking for suggestions for a starting point and a turnaround point. Want to keep it short and simple because I want to make sure he enjoys it. I am familiar with Califon since I fish Ken Lockwood Gorge several times a year. Would prefer to bike in that area if possible. Any suggestions would be appreciated. Thanks,