Timpanogos

It was the summer of 1847 our lives would be changed, a new people would come, not like the "big hats" of old. These people would build fences, claim lands and disrupt our culture and way of life. Bringing confusion as they spoke of their God and peace while sharing sacks of flour laced with broken glass. Brigham Young said "You can get rid of more Indians with a sack of flour than a keg of powder." Destroying us with what appeared to be acts of kindness. As our Timpanogos tribal leaders Kanosh, Tabby, Washakie, Little Wolf, Wanship, Little Chief, Kone, Blue Shirt, Big Elk, Opecarry, Old Battestie, Tintic, Sowiet, Angatewats, Walkara, Graspero and others extend their hospitality to Brigham Young and his followers, they were unaware of the bloodshed that would follow, some 150 bloody confrontations between 1847-70. (See Utah Black Hawk War; Black Hawk's Mission of Peace)

[Timpanogos Tribe Website]
[Lamanite Truth Website]

On another website the story is attributed to a woman named Illa:

“Illa shared the story of her family getting a sack of Flour from the Mormons, when Old James Reed saw the flour he dumped some of it on the table and brushed his glove covered hand across it exposing the broken glass fragments hidden inside. She always warned against taking food from Mormons because of this,” Said Mary Meyer.

[Black Hawk Productions Website]