More than a million people have checked-in at , which is the site of ongoing protests against the construction of a $3.7 billion gas pipeline through the reserve considered sacred by Native American Indians.
The sudden check-in influx came following the circulation of a post which called on people to use the function at 'Standing Rock' as a way of countering what it called police "attempts to disrupt the prayer camps" by "targeting" protesters.
The Morton County Sheriff's Department responded by calling the accusations "absolutely false" in a Facebook .
Protests, which date back to 2014, relate to the pipeline's location under the Missouri River, the primary drinking water source for the Standing Rock Sioux, a Native American tribe of around 10,000 people.
The pipeline is a project of the Texas-based Energy Transfer Partners project, and if completed, would cross four US states.
People continue to check in from across the US and worldwide.
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