UPPER KLAMATH LAKE, Ore. - A conservation organization used thousands of pounds of explosives Tuesday to breach a dike and begin the process of flooding about 2,500 acres of land it owns here to help save an endangered fish.

Scientists believe a primary cause of the suckers' decline was the loss of marshlands in the lower parts of the Williamson River, which flows into Upper Klamath Lake, the organization said. Some of that habitat had been converted into farmland in the 1950s when about 22 miles of dikes were constructed, the group said. 

Since 1996, when The Nature Conservancy began acquiring land in the river delta, ecologists have removed some of the dikes and restored about 500 acres of wetlands, the group said. Tuesday's levee breach will continue that effort; ultimately the group plans to restore 6,800 acres of wetlands in the area.

Tuesday's blasts will help slowly fill in that farmland with water. Officials expect some parts to be 2 to 3 feet deep by next spring, when the lake is at its highest.

The Nature Conservancy said it had explored alternatives but demolition was the only safe way to breach the levees.

To learn more about the group's Williamson River Delta Preserve, click here.

To download the wetlands restoration plan, click here.