Marines deep in Orange County canyon country hoisted heavy military-grade containers from trucks and pulled out shovels, axes, crowbars — equipment to dig holes for C4-grade explosives.

The mission Tuesday was unusual, if not a first. The plan was to blow up three small dams on Silverado Creek. Boulders would fly, concrete would crumble, rock shrapnel would tear into anything soft.

Just before sunset Tuesday night after a long day of preparation, an explosion demolished the first dam.

“It came apart easier than expected,” said Darrell Vance, district ranger for the National Forest Service.

Two more dams in Silverado were expected to be blown up Wednesday.

In the days to come, five dams in the Holy Jim Canyon are scheduled for blasting. No human is allowed within 1,000 feet when the C4 goes off.

Tuesday was thick with tension, perhaps not unexpected when explosives are to be used in an area designated as protected wildland. Yet this mission is especially complicated.

Officials who consider themselves environmentalists split with civilian environmentalists over the fate of the dams, some of which are believed to date as far back as the 1930s.

Read the whole story from The Orange County Register.