SOLWAY, Minn. – These were among policing tools used in the first day of the Treaty People Gathering protest against the Line 3 pipe being built across northern Mimnesota boreal forests by the Canadian company Enridge.

> Sit-downs. The most easily arrested had laid themselves on dirt roads and construction paths. They were carried away one at a time

> Chained resistance. Police in riot gear broke through steel fences which protestors and scaled and climbed atop diggers and transformer boxes and chained themselves to construction equipment. With bolt-cutters police cut the chains. Protestors offered no resistance and were guided single-file to police buses.

> Sonic weaponry. At one site at least, police used a crowd-dispelling sonic device on the protesters. The LRAD long range acoustic devices, although designed for communication can be rigged to emit an extremely high-decibel piercing emission for crowd control – a controversial police application.

> Helicopter downdrafts. A. U.S. Border Patrol helicopter descended on at last one site and, from 20 feet up, forced a blinding and choking combination of dirt, dust and debris at protestors.

> Boat blockade. One arrest was at an old fiberglass pleasure boat on a trailer that was situated with bamboo and steel cable to block a work site A woman had perched a beach chair at the boat and waited with a homemade device made of rebar, PVC pipe and handcuffs to make it more difficult for authorities unseat her. They did.

Earlier: How many Line 3 arrests? Sheriff mum