Mileage (location) markers of transportation centerlines within Gilpin County, Colorado.

Mile markers for select Boulder County roads and CDOT roads. The Boulder County roads were initially selected based on historic precedent, referencing printed maps in the Public Works (formerly Transportation) Department. Markers for more roads may be added after further review. Historic roads included some within municipalities, and mile markers were retained for those roads, regardless of annexations.Mile marker points along County roads were measured using GIS. Each road length was calculated using GIS, depending on accuracy from the Colorado StatePlane coordinate system and then accounting for slope from a 2.5 foot DEM. Markers, every quarter mile, were located along routes using a linear referencing method.Markers on CDOT roads were selected from a feature service owned by them. The selected roads were based on the Road_Map_Roads feature class.Note: Road Maintenance mile posts will be move based on markers in this dataset.