An oil spill along the coast near Santa Barbara has dumped about 21,000 gallons of oil from a 2-foot pipeline onto the shore, creating a 4-mile slick in the ocean, forcing an emergency cleanup and leaving the fate of the beaches unclear ahead of the three-day Memorial Day weekend.

Coast Guard crews responded after reports of an oil slick in the ocean, also seen on the sand at Refugio State Beach, around 12 p.m. Tuesday. The slick was initially estimated to be about a half-mile long but was reported to have spread to 4 miles wide by 3:30 p.m.

Capt. Jennifer Williams of the U.S. Coast Guard said the spill will have to be constantly monitored to minimize environmental damage.

"It's a moving target. Unfortunately it's not an exact science when we're dealing with changing conditions out there," Capt. Williams said. She added that wildlife should be able to recover from the damage caused from what she classified as a "medium" spill.

Video from NewsChopper4 showed that the spill happened in a portion of the pipeline above ground on land near the beach and made its way down to the sand and into the water.

Locals were concerned about the impact the spilled oil will have on wildlife.

"We are just kind of looking at the lay of the land here, and it's just devastating," resident Josh Marsh said.

"Tomorrow we'll probably (see) more of a sign of how bad the wildlife affected will be," Morgan Miller, who went to the beach to aid affected wildlife, added.

Refugio State Beach was evacuated, and warnings were issued for nearby El Capitan State Beach, as the oil slick moved south toward the popular camping spot.

Officials declined to speculate if the beaches would be open by the three-day Memorial Day weekend.

The U.S. Coast Guard is dredging the water and attempting to pick up the oil. Wildlife specialists have been called in to comb the coastline for affected animals.

The pipeline is operated by Plains All American Pipeline, L.P.

"Earlier today, Plains All American Pipeline, L.P., became aware of a crude oil release from its 24-inch Las Flores to Gaviota pipeline in Santa Barbara County. Initial reports indicate the released oil reached a culvert leading to the Pacific Ocean. As a result, the spill has impacted ocean water and the shoreline. At this time, the amount of released oil is unknown," read a statment from the company.

"Plains shut down the flow of oil in the pipeline and has initiated its emergency response plan. The culvert has been blocked so no additional oil is reaching the water. Plains is working with local officials and first responders on site to begin clean up and remediation efforts."

"Plains deeply regrets this release has occurred and is making every effort to limit its environmental impact. Our focus remains on ensuring the safety of all involved. No injuries have been reported at this time."

Representatives from the Santa Barbara County Office of Emergency Management, Exxon Mobil - which operates a nearby facility - and the Santa Barbara County Fire Department are on scene of the spill.

The leak was stopped by mid-afternoon, a Coast Guard spokesman said.

