Abstract: A rugged hand-held mobile computing device for a forester to collect and use dendrometric data from trees and tree stands is claimed. The device includes a processor which operates in connection with a memory, a user interface, a GPS receiver, a sound sensor capable of emitting an ultra-sonic pulse and a computer readable code embodied on the memory. The device communicates with a transponder by way of the ultra-sonic pulse emitted by the sound sensor. The transponder also emits an ultra-sonic pulse back to device. The device calculates the distance traveled based on the knowledge of the speed of the pulses. The memory, which also includes basic mapping software, uses the data to update a map in real time with the location of the trees and other information collected.