There is no direct way to insert the start and end elevation of a line feature as attribute values. The Interpolate Shape tool can only add z-values to the feature geometry, and the Add Surface Information tool can only add the mean elevation of a feature by defining the elevation surface. However, it is possible to add the start and end z-values to a line feature as attribute values by combining the Interpolate Shape tool and a Python script.
The instructions provided describe how to add start and end z-values to a line feature.
import arcpy #Specify the desired workspace. input_fc = r'<workspace>\<line_feature>' #Modify this part according to the specified field names created in step 2. myfield1 = "Z_Start" myfield2 = "Z_End" myshape = "SHAPE@" #Iterate between rows available in the attribute table of the line feature and input the z-values. with arcpy.da.UpdateCursor(input_fc, (myshape, myfield1, myfield2)) as cursor: for row in cursor: geom = row startpt = row.firstPoint endpt = row.lastPoint row = round(startpt.Z, 2) row = round(endpt.Z, 2) cursor.updateRow(row)