arcMap edit 2

right click -> define new feature

select yellow area -> editor -> buffer -> template -> buffer zone

create a 300m buffer

select yellow area -> editor -> clip -> distance 0

enable intersection snapping 

select goose lake -> select cut polygon -> trace alone the river -> finish sketch 

right click editing feature frame -> activate

select road segments -> editor -> edit vertices

right click on segment -> change segment -> circle

move segments to road

select delete vertices, draw a rectangle around extra vertices

change north segment to Bezier  to follow the road

reference:

https://desktop.arcgis.com/en/arcmap/latest/manage-data/editing-fundamentals/exercise-2d-editing-vertices-and-segments.htm