Glad you asked...
In order to establish a phone tree there will have to be one person who is the initial caller to two other people and from there on in, each person has two other people to call. Phone trees are used to spread news of closings, delays ad other work, family or education related messages.
Then again, this answer might help you...
To make a phone tree, simply coordinate volunteers who are able to pass along calls to others. For example a message could be given to three callers who will call three people and the three people they call would call three others and so on. You can purchase a phone tree system that works with a computer to make automated calls.

