Shields River Road provides access to over 113,000 acres of the Custer-Gallatin National Forest within the Crazy Mountains. The roadway parallels the Shields River which begins in the Crazy Mountains and flows 62 miles to the confluence of the Yellowstone River east of Livingston. Shields River Road offers scenic views of mountain peaks, rivers, and streams. Over the years, several other access points to the national forest have been closed because of landowner disputes. This has made the Shields River Road corridor the most heavily utilized road by recreationists on the west side of the Crazy Mountains. Recognizing the deteriorating conditions of the roadway, and the use as a major access to federal lands, the Federal Highway Administration (FHWA), in partnership with Park County and the United States Forest Service (USFS), developed this planning study to identify potential improvements to the Shields River Road corridor. A key outcome of the study is the development of recommendations intended to address the transportation and access needs of roadway users in the study area. The recommendations define the most critical needs of the corridor and will help the study partners prioritize and allocate resources to address the needs. This study reviews and considers environmental and social issues and aims to reduce planning time and minimize construction costs through the demonstration of feasible improvement opportunities. The intent of this Preliminary Engineering Report is to analyze roadway conditions, identify areas of concern, and develop improvement options for the study corridor. The transportation conditions analysis includes a planning level examination of the corridor based on a variety of information sources and field reviews. Goals and objectives for Shields River Road are also identified based on a comprehensive review of existing and projected transportation conditions. The analysis, together with the stated goals and objectives, influenced the development of potential improvement options intended to address the identified issues and areas of concern.