I can't think of any scenario where a Dad and his Son go into the woods to camp in a place where other men are discussing their Faith and modeling Jesus would be harmful to the boy or the other men.
We should keep in mind the following, however:
Your son should be able to walk up to 8 miles in a day.
You are responsible for his safety and well being on the trail and in camp.
Right now, this is primarily a Mens Small Group organized for the purpose of eventually reaching out to Youth Ministries and disadvantaged youth.
God may will that it become a Father/Son Small Group, or that a Father/Son Small Group grows out of this.
In fact, I rather hope that it does.