Protesters like Kate Gordanier-Smith said it was their worst fear come true, but were taking it all in stride.
"I didn't come here to be angry," she said. "I came here to hold on to hope and to be a witness for change".
Others weren't so philosophical and police made at least three more arrests Friday night.
Among those arrested Friday were environmental activist David Suzuki's grandson Tamo Campos and Simon Fraser University scientist Lynne Quarmby.
Quarmby is taking place in a march up the mountain this morning and said in a statement, "more individuals are considering arrest."
Heavy machinery is now in place and Kinder Morgan says it is test drilling roughly 250 metres into the ground as part of its survey work for a proposed expanded pipeline.
Protesters are being arrested and charged with civil contempt for defying a court injunction to stay clear of the work site and let the pipeline company do its work.
The company obtained a court injunction a week ago Friday to have protesters removed from the site, but police did not step in to enforce it until Thursday morning.
Drilling 24 hours a day
In an emailed statement, Kinder Morgan says it will be drilling six-inch test-holes — work that will be conducted 24 hours a day for the next 10 to 12 days.
The company says it is committed to minimizing any impacts and restoring or compensating for any disturbance to Burnaby Mountain. The drilling is taking place in a City of Burnaby designated conservation area.
"Ultimately, if the project is approved, there will be no surface disturbance on Burnaby Mountain because the tunnel, at its deepest point, will be approximately 160 metres below surface," the company said in its statement.