Grand Isle, Louisiana (CNN) -- The gate was wide open, so I just drove down the dirt road without stopping. A few hundred feet past the gate, a dust cloud kicked up. I slowed down, veered right, and stopped. A white Ford truck blocked the road to Elmer's Island.

A short black haired security guard sat behind the wheel. He stepped out of the car, and told me to turn around. I ask him "Why?"

"You can't be on this beach without clearance," he says coldly. "What if I make a run for it on foot?" I joke. "It would be trespassing," he says. "Who do you work for?" I ask. "BP," he says. "BP doesn't own this island," I tell him. "The state does. It seems they should be the ones telling me to leave."

It turns out that while Elmer's Island belongs to Louisiana, for all intents and purposes it's managed by BP.

The man walks back to his truck and radios his boss. An hour later, I'm at the BP spill response headquarters several miles down the road in Grand Isle, and a CNN attorney is on the phone with a cleanup manager named Jim McHale. He brings a small posse with him: security guards, some guy in a polo shirt, and a U.S. Coast Guard officer. Everyone is looking down at their feet, kicking the gravel in the parking lot while McHale talks on the phone.

I ask the gate guard why all the security is needed for Elmer's Island.

"I don't know," he says. "They just don't want nobody down there. I'm surprised they are even talking to you about it."

'Cleaner than before the spill'

Thick, dark oil started washing up on Elmer's Island exactly one month after the Deepwater Horizon platform caught on fire in the Gulf of Mexico. The oil seeped into marsh grasses and choked the shore, spilling over protective booms and other barriers put up to protect the beach.

The polluting of Elmer's Island was a major blow to the Grand Isle community's psyche. A trip to the 250 acre beach has been a tradition for many bird watchers, fishers and families looking to play in the surf with their children. The economic and environmental losses hit families hard.

Meanwhile, neighbors got suspicious when the gates to the beach were locked and the public shut out, says Grand Isle resident Karen Hopkins.

"It was a gem," says Hopkins. "But from the very beginning, we didn't trust BP. Why? Because they locked the gates right off the bat when the oil came ashore. They didn't want us in there because they didn't want us to see what a mess had been made, or how they were cleaning it up."

The day after the run-in with the security guard, Jim McHale is showing me the beach. McHale works for SEACOR Marine, a contractor hired by BP to clean up Elmer's Island and other areas around the Gulf. A Louisiana Wildlife and Fisheries marine biologist drives us in a state owned truck, and we're joined by a BP hired environmental monitor. McHale says the security guards watch over the cleanup equipment.

BP also issued a statement about the security guards: "We have security guards on Elmer's Island ensuring the security of the equipment we have there. The island remains accessible to the public."

As we drive the shoreline, the only cleanup equipment I see are a few rakes, shovels and trash cans.

The beach looks clean. There is no visible oil, no tar mats, no dead animals washing ashore. The only tar balls we find are caramel colored, walnut sized lumps that workers have to dig for.

"Elmer's Island is cleaner than before the spill," McHale says. "I would fish here anytime I would have the opportunity. The seafood is extraordinary. I've eaten the shrimp, I've eaten the crabs, I've eaten the redfish. I have no problems with it."

I ask him if he would bring his family here to play in the surf and dig in the sand.

"Most definitely," he says.

The next morning, before the cleanup work begins, I have a local fisherman take me out on a boat, and we see plate sized, gooey black tar balls dotting the shore.

Carcinogenic hot-spots?

The tar balls are problematic, but even more concerning are the potential pools of oil just under the surface of the sand. Louisiana State University Environmental Scientist Ralph Portier found what he describes as "hot-spots" of carcinogenic hydro-carbons under Elmer's Island.

"It's chronic exposure, a life time of exposure, long term exposure (or) consumption of some of these things that we worry about."

Portier cautions the findings from last summer are dated, and that the hot spots may have degraded.

"The data sets that we generated earlier in the year were data sets not for making these kinds of decisions in 2011," Portier says. "They would have been appropriate for making decisions last summer in 2010."

Louisiana state officials say BP is pushing to have Elmer's Island declared safe and re-opened. BP did not return a request for comment by deadline. But Portier's dated test results have raised enough red flags to keep the beach closed until more tests are done. Louisiana Wildlife and Fisheries Secretary Robert Barham says he's asked for the federal government to test for more hot spots. He says officials with the U.S. Coast Guard kept telling him the testing would be completed.

"We can't find evidence that (the Coast Guard) probed on Elmer's Island," Barham says. "We've gone back to them and asked them, 'If there is something we have not seen, or if there is additional information, give them to us.' But there was no follow-up that we can find of analysis of those cores."

"I'm not concerned about how it looks visually," he continues. "They went out there and skimmed the tar balls and picked up all the trash. And the beach looks quote 'cleaner than it did before the oil spill.' The fear we have is there is something there that will pose a health risk."

CNN contacted the Coast Guard three different times about those test results and other environmental questions regarding Elmer's Island. The Coast Guard hasn't responded.

'Unlock those gates'

At night, the security guards lock the gate to Elmer's Island and go home. The gate has always been locked at night, but the difference now is few locals try sneak by them to fish at night.

Commercial fisherman Ricky McKnight has lived in Grand Isle for about five years. He says Elmer's Island used to be a great place to fish, especially during the quiet hours. Since the spill McKnight has helped with cleanup.

"What's happening here, what you saw when you went on that beach, with those clean beaches, it's show time," McKnight says. "That's what they wanted you to see. But let me ask you: If it was safe, do you think they would keep it guarded like that?"

We're sitting on his screened porch talking, listening to the lapping of the waves on the shore. His wife, Karen Hopkins, shakes her head in disgust.

"Why is it still locked? If it's cleaner than it was before, unlock the gates!" says Hopkins.

"We Cajuns in Louisiana are very forgiving, hard-working, fun-loving people, but we are not stupid. They say it's clean, then unlock those gates!"