Lives were put at risk at Yale Beach in the Fraser River Canyon last week when someone contaminated four boat gas tanks with sugar.
No one was injured but it did cause one of the boats to stall out on the river, according to reports.
Vanessa Peters, councillor for Yale First Nation, fired off a letter Aug. 10 after the incident, addressed to Yale chiefs, leaders, and "fishermen and fisherwomen," calling the incident "disgraceful" and "criminal."
The tanks sabotaged at Yale Beach were where "our Sto:lo neighbours/family" launch their boats to fish, she wrote in the letter, and most of those impacted were her family members.
At least 10 people were placed at risk.
"Yale First Nation leadership is not in support of any action that puts people's lives in danger," Peters said, adding that she hoped it wasn't a Yale FN member who did it.
"If a loss of life or lives resulted from this action it would be considered premeditated murder," Peters wrote.
She called it "cruel" and "senseless" and told the person responsible that if this was to make a point, "to myself or Yale First Nation leadership, then you need to deal directly with me or us, not put the lives of our family in danger."
Grand Chief Doug Kelly, president of Sto:lo Tribal Council was troubled by the reports of spiked gas tanks in the canyon, and hoped whomever is responsible "will cease and desist" from further actions.
"I don't know that they fully realized the dangers of what they did," he said. "We don't know who did it, and cannot assign blame."
Past differences over access to traditional fishing spots, sacred sites, and dry rack camps in the canyon have actually been resolved recently between the communities who share a big swath of the Fraser River.
A recent ceremony that brought together members of Yale and Sto:lo leadership to restore a Sto:lo memorial plaque of their ancestors, known as I:yem memorial, was meant to create peace and harmony.
"We carried out that ceremony months ago as a way of resolving past differences, and as a way of making right what had been wrong."
The current chief and council of Yale First Nation had willingly opened the door for Sto:lo Nation to do that ceremony, and it effectively put the outstanding issues to rest.
"Good will was restored and I think we are in a really good place now, despite what happened," said Kelly.