"It had gotten to the point that we were marketing a river tour and our hula and music offerings. We were embarrassed to mention the Fern Grotto. It was just a stop at the top of the boat tour," said Kamika Smith, general manager of Smith's Motor Boat Service, which has been running Fern Grotto tours for 60 years.

Smith's grandfather, Walter J. Smith, launched the concept in the 1940s. Barges full of tourists run two miles up the Wailua River all day long, entertained with hula and Hawaiian song, as well as tales of the Wailua area. Just above the fork in the river, the barges are tied up and visitors wander to an overhanging cliff with a cave at its base. Until 10 years ago, the cliff was green with ferns, giving the area its name.

The ferns died because the cane fields at the top of the cliffs were taken out of production and irrigation stopped, leaving no water to seep through the rocks and drip along myriad crevices into the natural amphitheater.

The state Parks Division, which operates the grotto, has undergone severe staffing cuts and was unable to do anything to help the ferns grow back. But last year, the Hawai'i Tourism Authority provided $245,000, to which Kaua'i County added $50,000, to solve the problem.

Nishek said his staff worked with state parks, the county, Smith's company, Lihu'e Land Co., the East Kaua'i Water Users Cooperative and other organizations under the contract. County tourism liaison Nalani Brun said Kaua'i Nursery and other committed partners donated services worth more than $100,000 on top of the contract amount.

Much of the work included extensive clearing of hardy overgrowth from walkways and removing dense branches overhead that were cutting off sunlight. Workers repaired sidewalks, removed fallen rocks, reshaped sedimented areas below the grotto, repaired the restroom and improved the area.

Clearing the vegetation was the biggest job, but perhaps the most significant work was the engineering required to restore moisture to the grotto walls. Smith said that before sugar cane was planted above, the walls were probably dry. Then a century of irrigation of the land atop the Wailua River cliffs created a super-wet environment that promoted fern growth. When the irrigation stopped a decade ago, the ferns began dying.

The county arranged with landowner Lihu'e Land Co. and the East Kaua'i Water Users Cooperative to restore water to the old Lihu'e Plantation Co. Reservoir 21, which sits on the plateau above the grotto. Nishek's crews installed solar photovoltaic panels that feed a pump, and also established a siphon system to run the water to the cliff edge.

The new system pipes water along the clifftop, allowing some to flow over the side in a waterfall like the one that was there before cane cultivation ended, and some to seep into the ground. The groundwater then hits underground rock formations and finds its way to the cliff face.

After the ferns, the most impressive feature of the Fern Grotto is the way music propagates off the face of the rock cavern. Boat tour crews take advantage of it by singing the traditional song, "Ke Kali Nei Au," at the base of the cliffs.

"The song echoes through the valley. The acoustics there are just incredible," said Brun, a soprano who started dancing hula there as a teenager, and started singing at the grotto at age 17 "when I found out singers made more money."

"Ke Kali Nei Au" became known as the "Hawaiian Wedding Song" in the Elvis Presley movie "Blue Hawaii." Presley sang the words in English at his movie wedding aboard a double-hulled canoe at the Coco Palms Hotel lagoons, a couple of miles downstream from the Fern Grotto. But the song's original Hawaiian lyrics had been sung in the grotto years before.

Brun's father, William Kaauwai, was a Gray Line bus driver at a time when the drivers would climb on the boats and entertain Fern Grotto tours. Kaauwai's guess is that the English words to "Ke Kali Nei Au" were written after someone heard the melody at the grotto. It is called the "Hawaiian Wedding Song" entirely because of the Elvis connection.

"It's not really the wedding song. 'Lei Makamae' is," Brun said, referring to the traditional "Lei Aloha, Lei Makamae." Both are love songs written during the first half of the past century by famed Hawai'i composer Charles E. King.

At this point it may be too late to set the record straight. Couples from around the world come to be married at the Fern Grotto, and the wedding song they demand is the Elvis version.

But it might more accurately be called the "Fern Grotto Song."