Height and dating not updating since new heads added
If alone pick a distinctive point on the ground to mark this point.
The distance from the base of the tree to this point is equal to the height of the tree.
Of the various methods of approximating tree heights, the best options, requiring only a minimal amount of equipment, are the stick method and the tape and clinometer (tangent) method.
Tree height can be measured in a number of ways with varying degrees of accuracy.
First try to view the tree from several different angles to see where the actual top of the tree is located. This will eliminate the greatest potential for error.