Tens of thousands of new, native plants have been sunk into the sandy soil at Hells Gate Habitat Management Unit south of Lewiston.
Across the Snake River, willow and cottonwood cuttings have been carefully planted in the riparian areas of the Asotin Slough Habitat Management Unit. Given time and favorable growing conditions, Mark Graves, a wildlife biologist for the U.S. Army Corps of Engineers at Clarkston, said the plants and trees will provide habitat for a diversity of wildlife.
Graves is in charge of managing land purchased or set aside to mitigate for wildlife habitat that was lost when Lower Granite, Little Goose and Lower Monumental dams were built. An assessment showed the two units were lacking in some areas and spurred the project.
The recent repair of an irrigation system at Hells Gate made it possible to plant in several draws that cut westward from a wide bench toward the Snake. Graves said those plantings make sense because taxpayers have made a large investment in the irrigation system and past plantings in the draws.
But he also wants to step back from his agency's past reliance on sprinklers to create imitation riparian areas. Instead, Graves is concentrating efforts to enhance true riparian areas along rivers and creeks and using xeric species, those that can thrive in arid conditions, in nonirrigated areas. Species like big sage, bitter brush, salt brush and buckwheat are being planted on the dry, west-facing hillsides, while willows and cottonwoods are being planted near the water's edge.
“We are moving away from putting resources into new plantings in irrigated areas and we are moving down to the river's edge to focus on true riparian areas and the xeric sites,” he said.
The work at Hells Gate is being conducted in conjunction with efforts to more closely manage the high level of recreation there. Although the area was set aside to provide wildlife habitat and hunting access, it's popular with hikers, bikers, dog walkers and horse riders. Managers worry the heavy human presence is reducing the quality of habitat. So Graves and others are trying divert some of the trails there away from areas with the best cover for wildlife, and to convince people to stay on trails and out of places with the best habitat.
At the same time, another recently completed project to stabilize a large section of bank along the Snake River, has included plantings of riparian species and trees like ponderosa pine and alders. The work included the installation of a restroom at the area's parking lot on Tammany Creek Road.
At Asotin Slough, thousands of willow cuttings are primed to spring up from the edge of the waterway that cuts through the unit. A walking trail and wildlife viewing platform are planned for the future.
“I'm pretty excited about all this work,” Graves said. “I'm hoping we'll have a nice wet spring and everything will have an opportunity to get established.”