District 9, established on October 11, 1923, is located on the eastern side of the Sierra Nevada Mountain Range. It encompasses both Inyo and Mono counties. The area ranges from the alpine settings and Sierra Nevadas to the low deserts and valleys. These extremes present many different challenges in designing and building streets, roads, and highways. The extremes in elevation range from Badwater in Death Valley, at an elevation of 282 feet below sea level, to Mt. Whitney at an elevation of 14,495 feet. The main route, both then and now, is U.S. Highway 395. It served mostly as a tourist route, however, there were some mining materials and farm goods being transported at that time. As the City of Los Angeles bought up the land to export water to thirsty people in the southland, farming was reduced dramatically. Mining also dwindled as ore veins played out or cheaper sources for the same minerals were found.
Today, the area is almost entirely dependent on tourism. Most of the roads and highways in 1923 were nothing more than widened dirt wagon trails. In fact, U.S. Highway 395, even with its modern paving and many four-lane sections, still follows the general alignment of the old wagon trail and some Native American routes through most of Inyo and Mono counties. At the time of the formation of District 9 in 1923, the district contained 332.4 desert and mountain miles from the Kern County line to the Alpine County Line at the Nevada Border. This includes many highways such as Highway 168 from Big Pine over Westgard Pass to Oasis, and Highway 120 from Lee Vining to Tioga Pass. Over the years, highways were improved by paving and widening, and additional roads were taken into the highway system. It was not until recent times (1960) that existing highways were widened and additional lanes were added to provide four-lane expressways on the main lifeline. Improvements continue to be made, and today U.S. Highway 395 is in the process of being almost completely four-lane from the Los Angeles area to Lee Vining.