Unfortunately, as an AI language model, I do not have access to up-to-date information about specific national park attractions. However, I can suggest some general tips for writing a tour guide summary about a national park point of interest:

1. Research the history and significance of the attraction: Who built it? When was it built? What was its purpose? Was it abandoned or destroyed, and if so, why?

2. Describe the physical features of the attraction: What remains of it today? What architectural or natural elements are particularly noteworthy or unique?

3. Highlight any special events or activities that take place at the attraction, such as guided tours, hiking trails, or educational programs.

4. Provide practical information for visitors, such as hours of operation, admission fees, and accessibility.

5. Finally, emphasize the reasons why this attraction is worth visiting. What makes it stand out among the many other points of interest in the national park? What can visitors expect to gain from their experience there?

By considering these factors and conducting thorough research, you can create a compelling tour guide summary that will inspire visitors to explore the Morning Star Mill Ruins or any other national park attraction.