I am currently working on a project at work to determine the river miles of over 3000 sample locations along a river. I figured out how to use dynamic segmentation to divide the river into smaller increments of measurements to determine a more accurate location of the sample locations. However, not all the sample locations feature points intersects along the line. Are there any gis tool(s) where I can join the the attribute of the line to the points perpendicular to the line to determine the river miles of the points? I know that there are tools, such as nearest neighbor distance, buffering or spatial join to join the two feature. However, I am looking for a tool that would join the points perpendicular to the line, not a join within a specific radius offset of the line location.