Abstract: Astronomical tourism represents a less-studied segment of sustainable tourism, where a dark night sky is the underlying resource. This article evaluates an astronomical tourism program, in this case at a national park with dark skies for observing. Bryce Canyon National Park (BCNP) in the southwestern United States has a well-developed astronomy program to serve visitors. The program consists of solar viewing during the day, multimedia evening programs, and night-time star gazing with telescopes. Depending on the specific measure used, it appears that up to 10% of park visitors may be involved with the formal Astronomy and Dark Sky Program and/or more informal astronomy activities. BCNP appears well positioned to take advantage of the dark sky attributes of the park and to educate visitors about the importance of maintaining and/or increasing the darkness of night skies. Potential future developments in the program may serve to further increase the number of visitors to BCNP.