Abstract of paper presented at the 2003 Annual Meeting of the Association of Engineering Geologists, Vail, CO, Sept. 25, 2003

RESEARCHING HISTORIC LAND ACCESS ROUTES IN COLORADO; ENGINEERING GEOLOGISTS PERFORMING RS 2477 STUDIES

McCalpin, James, GEO-HAZ Consulting, Inc., P.O. Box 837, Crestone, CO 81131, (719) 256-5227; mccalpin@geohaz.com; www.geohaz.com

Engineering geologists have strong qualifications to perform historical research into land access routes and rights-of-way, because they are familiar with topographic maps, map projections, aerial photographs, georegistration, registering historic maps with modern maps and aerial photographs, and methods of earthmoving and road construction. The field has grown in popularity with the increase of land subdivision and the building of “trophy homes” in rural Colorado. New landowners may not be able to build until they can obtain (condemn) a legal access across a neighbor’s property, and the neighbor’s reluctance to grant same may trigger a lawsuit. A major issue in the lawsuit will be whether the roadway under condemnation proceedings existed and carried “public traffic” before the land was withdrawn from the Public Domain of the United States, that is, was granted a homestead patent or was sold to an individual. If public use predated the withdrawal, then the roadway has a permanent public right of way under U.S. Law RS-2477, and the new landowner (as well as the general public) can use it to access his parcel without initiating a condemnation action.

Patent dates in central Colorado range from the 1880s to 1920s, so determining whether roads existed before or after patenting requires examination of historic planimetric and topographic maps from that period. Typically, aerial photographs were not taken before 1934, so roads built before and during the homesteading period (wagon roads) can only be assessed from maps. After 1934 aerial photographs can be compared with historic maps, once they are correctly georegistered.

In one recent RS 2477 case in northwest Colorado, perusal of original General Land Office survey notes (1873, 1913), historic maps and aerial photographs proved that only about 20% of the length of a road under condemnation proceedings existed prior to patenting. The other 80% was built at various times as erosional events made some segments impassable, and as heavy earthmoving equipment became widely available. In this case, the plaintiff’s claim of an RS 2477 right of way was denied, and the rancher-client through whose land the current road extends was able to continue locking his gates and maintaining the road as private. In another access case in the Front Range, about 25% of the road under condemnation existed prior to patent. Several additional (and better) historic access routes were identified by examining digitized, georegistered maps and aerial photographs in MapInfo GIS. Routes included an abandoned pre-patenting wagon road that could be seen faintly on aerial photographs, and was shown on a 1906 USGS map, but not on any subsequent USGS maps, even those of larger scale. Also found were aborted roads from an early stage of land development in the 1950s and illegal roads made by neighbors, in this case to get a drill rig to his well site on the corner of his property. Tracking the evolution of road use in such rural areas requires observational and deductive skills commonly used in engineering geology.