Any person employed in the execution of any survey authorized by the Congress of the United States may enter upon lands within this state for the purpose of exploring, triangulating, leveling, surveying, and of doing any work necessary to carry out the objects of existing laws, and may establish permanent station marks and erect the necessary signals and temporary observatories, doing no unnecessary injury thereby, having first paid or tendered to the owner thereof the compensation or damages as prescribed in ORS 191.020 and 191.030.
Oregon Legal Code