US 550 at US 160 South Connection Supplemental Final Environmental Impact Statement (SFEIS)

The Federal Highway Administration (FHWA) signed the Record of Decision (ROD) for the US 550 South Connection to US 160 project, completing the Supplemental Environmental Impact Statement (SEIS) process. The federal agency, which oversees work on the national highway system (and roadway projects receiving federal funding), also signed the revised Section 4(f)* Analysis and the SEIS re-evaluation for the connection project on the same day.

The SEIS reevaluated a portion of the original 2006 US 160 Durango to Bayfield EIS project, and looked at both previous and new alternatives developed to reduce impact to historic properties, including the Webb Ranch, identified after the completion of the previous ROD. During the SEIS process several new alternatives were suggested by the public, which were evaluated by an independent team of engineers and planners. In addition, the federal Advisory Council on Historic Preservation participated in the resolution of adverse effects to historic properties. 

The independent team refined the original SEIS Preferred Alternative (Revised G Modified or RGM) to a design variation located further west, called Revised G Modified 6 (RGM6). The RGM6 alternative is the Preferred Alternative.  The independent engineering firm also helped with a preliminary assessment of the environmental impacts. Additional items such as cost, logistics and constructability were considered, which is consistent with screening criteria utilized in the SEIS. This work also included collection of updated data and outreach to La Plata County, the City of Durango, the Growth Fund Real Estate Group and property owners in the area.

In December 2014, CDOT hosted an open house to enable the public to view details of the newly refined US 550 connection to US 160 Preferred Alternative, as well as other alternatives that were developed by an independent team over the past year. 

The Notice of Availability of the ROD was placed in the Federal Register May 15, 2015.

*Section 4(f) is an FHWA regulation that governs the use of land from publicly owned parks, recreation areas, wildlife and waterfowl refuges, and public or private historic sites for Federal highway projects. The Section 4(f) evaluation requires two findings that must be demonstrated through coordination with FHWA and the State Historic Preservation Office (SHPO): (1) That there is no feasible and prudent alternative that completely avoids the use of Section 4(f) property; and (2) That the project includes all possible planning to minimize harm to the Section 4(f) property resulting from the transportation use (see 23 CFR 774.3[a]).