A. B. Greenwood makes mention of massacre is made in Report of Commissioner of Indian Affairs in November 1859.
A. B. Greenwood, "Report, Department of the Interior, Office of Indian Affairs, November 26, 1859," in Report of the Commissioner of Indian Affairs, Accompanying the Annual Report of the Secretary of the Interior, for the year 1859 (Washington, DC: George W. Bowman, Printer, 1860), 22
They [The Indians] have at times been compelled to either steal or starve; but there is reason to be apprehended that in their forays they have often been only the tools of the lawless whites residing in the Territory. In some of the worst outrages of this kind, involving the lives as well as the property of our emigrants, the latter are known to have participated. That this was the case in the atrocious and dreadful massacre at "Mountain Meadow," in September, 1857, the facts stated in the report of the superintendent, in regard to that occurrence, leave no room for doubt. The lives of from one hundred and fifteen to one hundred and twenty peaceable emigrants, of all ages, and both sexes, were inhumanly and brutally sacrificed on that occasion; some young children, only, being spared. These children, seventeen in number, were afterwards, under instructions from the department, found and taken possession of by the superintendent; and, Congress having made an appropriation to defray the expense, fifteen of them have been brought back and restored to their relatives in Arkansas. The remaining two are now probably on their way in. The presence of the military in the Territory during the last two years has, doubtless, tended materially to check these outrages; yet they still, and will continue to occur, so long as the administration of the criminal laws shall depend, in any degree, upon the fanatical and vengeful people who comprise the population of the Territory, who contemn and disregard our laws, and are, therefore, practically in a state of rebellion; and yet whom the presence of the army is absolutely enriching. Until some means shall be devised for the certain and prompt punishment of the perpetrators of crime, it will be impossible to protect the emigrants from being murdered and plundered by the lawless and fiendish whites and Indians; and I know of none that would be effectual for that purpose but declaring martial law, and placing the administration of affairs entirely in the hands of the military.