Twenty years ago, in Kenya's Central Province, a fence was built to protect the endangered black rhino. Now that fence has been expanded. The nearly completed barrier is 400 kilometers long. It encloses Aberdares National Park and helps promote ecosystem management, farming and public education. Voice of America English to Africa Service reporter, Sara Nics, at Aberdares, describes the scene.

On a steep, forested hillside, four men are unrolling wire mesh and nailing it to tall wooden beams. They carefully bury the base of the fencing in a three-foot trench.

Colin Church looks out at the view over Kenya's central province. He explains why the fence is being built along the edge of Aberdares National Park, "That is farmland, thousands of farmers on what is called the Kinangop Plateau, where there is mixed farming?very intense farming, right up against the fence."

Church is the executive director of the charitable trust called Rhino Ark, which has been building the barrier for the past 20 years.

So far, the project has completed about 350 kilometers of electrified fence, enclosing almost 2000 square acres of wilderness. 

He says, "The fence is seven feet above ground, three feet below ground. It stops wild pig?bush pig and forest hog and porcupine. The fence of course is impregnable to elephant as well. Essentially, this is a very, very strong barrier?. In these mountain systems, with their indigenous forests and with millions of farmers living on the lower slopes, you have to have a barrier that everyone respects: the elephant on one side, and the farmers on the other."

The original purpose of the project was to help stop the poaching of the black rhinoceros that live in these mountains. The fence helps keep out people who would kill rhino for their horns and other animals for their meat.

But over the past 20 years, the goal has expanded. Staff at the Rhino Ark, the Kenya Wildlife Service and the Kenya Forest Service came to understand that the Aberdares mountain range is more than a sanctuary for nearly two dozen endangered rhino.

The rain that falls on the mountains including neighboring Mt. Kenya is the source of five of Kenya's largest rivers. The water that is caught and filtered here irrigates land for many, many miles. The fence prevents people from illegally harvesting the trees that make the Aberdares such a valuable water catchment area.

One of the park's wardens, Augustine Njoga, says the fence also protects the farms on the edge of the park.  "The fence was meant to protect the community, as well as protecting especially the rhino sanctuary. It was being used as a barrier to prevent the wildlife from getting out and destroying crops."

42-year-old Crispus Karue has lived and farmed here on the foothills of the Aberdaress his entire life. The fence is only a few feet from his three-acre farm, "These are potatoes, these are maize; we want to plant cabbages. We do sell them at the market and we just get something little for eating."

Before it was built, he says, elephants, water buffalo and other animals would often cross the hedges and game ditches that were intended to keep the wildlife and humans apart:

"Before the fence, we [had] a lot of problems with the animals -- the elephants, buffaloes, water bucks and the rest. When there was no fence they [would] come here [and kill] our animals like cows, goats; even sometimes they kill even people. [They would] come out from the forest to get food and to eat here. So they destroyed our crops."

Now, he says, with the animals kept at a distance, he and his family harvest almost everything they plant.

Warden Njoga says the rate of conflict between humans and wildlife has decreased by about 90 percent where the fence has been built. The property values of neighboring farms have increased by 50 to 200 percent. More farmers' children are able to go to school since they are no longer needed to guard the fields against wildlife.

Njoga says now the farmers who live next to the fence help protect it. They also help the Kenya Forest Service educate border communities about how the fence keeps humans safe from wildlife and wild spaces safe from humans.

But Rhino Ark director Colin Church says fences are not a solution country-wide, "It's not the solution for wildlife all over Kenya. We stress it every time: wildlife can not be fenced in everywhere. There are realities that we have to face. One is that we have created an island ecosystem, so there could be long-term challenges. "

To address that, Church says the Rhino Ark and the Kenya Wildlife Service are looking for ways to create corridors for elephant and other wide-ranging species. They are hoping to link the Aberdares with its neighboring park, Mt. Kenya, and the open rangelands to the north.

Church expects the initial 400 kilometers of fence will be complete in early 2009. It's taken 20 years to get this far. But now that Rhino Ark has expanded its goals to include protecting both the ecosystem and human communities, the project is only just beginning.