In recent years, the policy and regulatory environment for intercity passenger rail in the United States has shifted dramatically, sparking a renewed interest in intercity passenger rail among policymakers, planners, and the general public. As the nation expands its passenger rail network, a better understanding of the mobility provided by short- to medium-distance corridors is desired. This study examined the Heartland Flyer, a 206-mile intercity passenger rail route between Oklahoma City, Oklahoma, and Fort Worth, Texas. Researchers analyzed responses to an on-board survey, distributed to passengers in April and July of 2009, to identify who was using the service and how the service impacted regional mobility. The key measure used to identify the mobility impacts was the passengers' self-reported alternatives for travel if the Heartland Flyer were discontinued. This study also identifies the economic impact of the rail service, measured through total spending on certain items (and the associated sales tax revenue). The findings of this study can be used in a variety of potential applications for all levels of passenger rail planning, including statewide rail planning, corridor-specific studies, and station-area planning, both in the southwestern United States and in other regions.