C.R.S. § 43-1-203

As used in this part 2, unless the context otherwise requires: (1) “Highway” includes bridges on the roadway and culverts, sluices, drains, ditches, waterways, embankments, retaining walls, trees, shrubs, and fences along or upon the same and within the right-of-way, and any subsurface support acquired in accordance with section 43-1-209 .