There's something lurking deep beneath the otherwise placid waters of Lake Isabella. It's been hunted by thousands, yet it continually evades capture.

Don't worry: It's not Nessy or Jaws or anything like that. It's simply one particularly valuable rainbow trout.

And for three days during the 23rd annual Lake Isabella Fishing Derby, that one trout could win its captor up to $40,000.

Though none of the 6,000-plus people who vied for the big-money fish last year managed to catch it, the Kern River Valley Chamber of Commerce, which coordinates the derby, assures anglers there's nothing fishy going on. According to Rex Emerson, communications director for the chamber, the organization does everything in its power to help ensure ambitious anglers traveling from across the country and throughout California have the opportunity to hook some prizes.

"The fish are actually raised on the lake, and we have hundreds of volunteers going out there to feed them three times a day," said Emerson. "We stop feeding them approximately five or six days before the start of the derby, so that gives the fishermen a better chance to catch the fish. But, sometimes the big-money fish are caught, and sometimes they aren't. That's just how it goes."

Even if the $20,000 fish isn't caught (the trout doubles in value if caught by someone wearing the official 2012 Lake Isabella Fishing Derby T-shirt), there will be plenty of other prize-winning fish in the lake.

In fact, the derby, hailed as the "world's largest amateur trout fishing derby," boasts more than $250,000 in potential prize money. And thanks to the recent sponsorships of two national bait and tackle suppliers, Berkley and Shakespeare, each individually tagged trout is worth more than ever.

"In previous years," said Emerson, "the lowest prize you could win was $20. But this year, the lowest value fish will be tagged at $50. And the majority of the fish will be worth either $50 to $100."

There will be 1,000 tagged fish, one worth the $20,000 prize, 10 worth $10,000, and all the rest ranging in value from $50 to $1,000. There's also the added thrill of not knowing exactly how much money you've won once you've caught one of those tagged fish.

Which is all part of the fun, according to Lake Isabella native Brett Ege, a 20-year derby veteran.

"When you pick up your registration at derby headquarters on Friday, they give you a sheet listing all of the tag numbers and their values," he said. "But when you get a bite, all you can see is that tag, and it's just really exciting to know that you could potentially have a lot of money at the end of your pole."

No stranger to reeling in a winning fish, Ege casts his line into the lake sometimes as frequently as seven days a week. Last year, he returned from his weeklong fishing vacation with a respectable $500 in his pocket.

And Ege witnessed his stepfather, Larry Loudermilk, hook a top-prize $10,000 fish in 2010, one of six caught that year.

"That was a crazy experience," he said. "When he caught the fish, we didn't even see the tag at first. And we didn't know how much the fish was worth until he went to derby headquarters and opened up the envelope. He about passed out when he saw all those zeroes."

While all the prize money functions as a decent lure for the fishermen and women out there, some might say the real value of the tournament lies in the late-winter boost it provides to Lake Isabella's economy.

"From a business standpoint," Emerson said, "this event is huge. Because it doesn't just effect one particular market. Whether people are in the food industry or the lodging industry -- whatever it is they have -- it's just a really big deal. What the derby does, it gives the whole community a financial shot in the arm that gets them through to Memorial Day and on to the rest of the summer."

While Ege agrees the increased revenue for his hometown is nice, the real benefit for him is the time he gets to spend around the campfire with his family.

"The best part for me is watching my kids reel the fish in," he said. "I have a 2-year-old boy and an 11-year-old girl, and the whole experience is just great. This is my only one week vacation that I take from work all year, and from the campfires, to the S'mores, to the games --we like to play horseshoes -- I look forward to the derby days all year."