Reddit mentions of Massacre at Mountain Meadows

If you want to know what the Church thinks read this book released fairly recently ago written by the assistant Church historian Richard Turley.

This book is considered, even by non-member scholars, the most rigorously researched account of events. Unlike many others, it was peer reviewed by an academic press (Oxford) and Turley had access to things just nobody else does and used everything at his disposal. (For example, your average historian off the street can't get descendants of these people to let them go through handed down family journals... but the assistant Church historian can as these people trust the Church.)

Anywho, the book concludes a lot of bad was done by a lot of high-ranking Church leaders, including Brigham Young, and many of the actions are inexcusable. However, the book also goes to great lengths to show it was physically impossible for Brigham Young to be the ringleader orchestrating everything as his critics claim.

Anyways, if you really want to know more read the book. It is a fascinating read and you won't find one more highly cited by professional historians on the subject for the foreseeable future.

Massacre at Mountain Meadows, by Ronald Walker, Richard Turley, and Glen Leonard. Yes, the authors are Mormon. Yes, the book was touted by the LDS Church. And yes, they do their best to try and disprove Brigham's involvement in the massacre. But this is still the best overview of the massacre so far. They have access to sources not available to individuals like Will Bagley and they're also able to approach a violent and dramatic event in history without overly emotionalizing it or losing focus. Stops right at the end of the massacre, however, and leave the bungled cover-up (for which Young was certainly responsible) for a still-future second volume.