Reports suggest that the slick is growing rapidly - one report said it had tripled in size in a day.
Louisiana Governor Bobby Jindal warned that the spillage threatened the very way of life of people in his state.
President Obama is due there on Sunday as is BP head Tony Hayward, who has been criticised over the BP response.
Sheen from the spill has begun washing up on the Louisiana coast, fuelling fears of environmental disaster.
Up to 5,000 barrels of oil a day are gushing into the sea after the British Petroleum-operated Deepwater Horizon rig exploded and sank last week.
Mississippi, Alabama, Louisiana and Florida have all declared a state of emergency, and analysts say the spill could rival the 1989 Exxon Valdez disaster as the worst in US history.
High winds
Mr Jindal said on Saturday: "This isn't just about our coast. It's about our way of life in Louisiana: our shrimpers, our fishermen, our coast that makes Louisiana a sportsman's paradise."
As pressure mounted on BP, the governor continued: "We certainly have passed the point of waiting for clean-up plans from BP or the incident commander."
The state had started developing "contingency plans", he added.
Worsening weather conditions have been hampering efforts to contain the slick, now more than 130 miles (200km) long.
Choppy seas meant that smaller boats - contractors and fishermen - that could have helped with the clean up were unable to go out.
Military planes deployed to spray oil-dispersing chemicals have also been grounded.
Rescue groups have been receiving their first patients - seabirds coated in oil - but a BBC correspondent in the area says that at the moment the wind is keeping most of the oil offshore.
The high winds are also forcing some of it over booms meant to contain it, however, and forecasters say that strong winds on Sunday could push more oil onto the Louisiana shore.
Wetlands off the Louisiana coast sustain hundreds of wildlife species, and a major seafood and fishing industry.
The president of Louisiana's Plaquemines Parish area, Bill Nungesser, said that the oil could cause enormous damage.
"We need to have something out there," he said. "Once it gets into the marsh it is too late. Once it gets behind these islands, through these little canals, you will never clean it up."
Reports suggest that the slick is growing rapidly. Experts from the University of Miami said that the slick had tripled in a day, citing satellite images.
Two natural gas platforms in the Gulf of Mexico have halted production because of the spill and one of them has been evacuated as a safety precaution.
The command centre co-ordinating the response said that the percentage of gas production affected was less than one-tenth of one per cent of the Gulf of Mexico's daily total.
http://news.bbc.co.uk/2/hi/americas/8656415.stm
as if Louisiana hasn't been pounded enough of late.