MADISONVILLE, La. -- Darkened only by shelling from Civil War gunboats, the Tchefuncte River lighthouse has provided a beacon for boaters on Lake Pontchartrain for 171 years.

Now the destruction that ships' cannons only could do temporarily, coastal erosion threatens to do permanently.

The oldest active lighthouse in the state, the conical tower remains structurally sound, said Jay Martin, executive director of the Lake Pontchartrain Basin Maritime Museum. A couple of grants the museum has received should pay for needed painting, interior repairs and fixing cracks that have appeared between some of the exterior bricks.

What worries Martin and other lighthouse lovers is the rapid disappearance of land around the foundation. Erosion has already cut off the lighthouse from road access and will soon isolate it from shore.

Destruction of the lighthouse would not only be a historical loss, but also mean the loss of an important navigational aid that helps recreational and commercial mariners day and night, Martin said.

"Over time this will be gone," Michaelyn Lombard said of the land upon which the lake's waves lap a few steps from the entrance to the 43-foot conical tower.

Land once gripped by the roots of cypress trees has disappeared in the absence of those trees that were logged 100 years ago, said Lombard, a Southeastern Louisiana University biologist who is guiding an effort to replant cypress trees in the area.

"Cypress trees held this land together," said Martin, who thinks replanting the trees and additional work can restore much of the land around the lighthouse.

In fact, he hopes to rebuild enough land in the next few years to return the lighthouse keeper's cottage to the site. That would provide an early step to make the lighthouse an important attraction for school groups and tourists interested in the area's history.

The cottage, where lighthouse keepers and their families lived in isolation, was rebuilt after it was torched during the Civil War.

The U.S. Lighthouse Service built the first lighthouse on the site in 1837.

The lighthouse was particularly important because the Tchefuncte was the most significant commercial waterway running into the lake, said Martin, who notes that the river continues to have commercial traffic in addition to the numerous recreational boats that now use it.

A whale oil lamp and a Fresnel lens provided the lighthouse's first beacon. The lens, handmade using a series of prisms, magnified the light, making it visible for 10 to 15 miles, Martin said.

Each evening the lighthouse keeper ascended the spiral staircase to the iron lantern room to light the lamp. At midnight, he would return to light another.

In the early days, the lighthouse provided not only a navigational aid, but also refuge for mariners in trouble, Martin said.

Bombarded in 1863 and subsequently occupied by Union troops, the tower was rebuilt in 1867 using the same foundation and bricks, Martin said.

Eventually the lighthouse became automated and powered by electricity, which is currently generated by solar panels.

In 1999 the U.S. Coast Guard transferred ownership of the lighthouse to the town of Madisonville. The museum manages the lighthouse for the town.

Now the lighthouse mainly helps people stay in the tricky Tchefuncte River channel, which extends well into the shallow lake.

Martin said the lighthouse helps boaters to avoid tearing the bottoms out of their craft on the cypress stumps that lurk beneath the surface as remnants of the swamp that once bordered the lake. Battered by Hurricane Katrina in 2005, the damaged lighthouse

has continued its operations.

The museum's board made restoration of the lighthouse its top

priority this year, said Jay Blossman, board chairman.

The museum has received a $25,000 grant from the Institute of

Museum and Library Services and the Southeastern Museum Conference

to stabilize the lighthouse and begin its restoration. The grant is

part of Hurricane Relief Awards presented to libraries and museums

impacted by Hurricanes Katrina and Rita.

The SLU Developmental Foundation added another $25,000 for that

work.

Once the lighthouse is repaired, the museum hopes to make it

accessible to the public, Martin said.

He foresees 30,000 people a year eventually visiting the

lighthouse