GREEN RIVER - A huge portion of the century-old Cross Lazy Two Ranch in Sublette County will be conserved under a permanent conservation easement announced this week, officials with the Green River Valley Land

Trust said.

The historic property to be preserved under the easement includes a portion of the Lander Cutoff route to the Oregon Trail, which was used by as many as 500,000 pioneers as they migrated west.

The Sublette County Centennial Ranch, operating under the Cross Lazy Two brand, is owned and run by Tim and Jody Thompson of Big Piney.

Land Trust officials said the easement agreement will result in 4,410 acres of crucial wildlife habitat on the Cross Lazy Two Ranch being preserved for future generations.

Trust executive director Lara Ryan said she believes the project is the largest one-time easement purchase in Wyoming history in terms of acreage.

The Cross Lazy Two Ranch is located about 12 miles west of Big Piney in southwest Wyoming.

Ryan said the easements will ensure that working ranchlands, wildlife habitat and the scenic views that pepper the property will remain available for Wyoming residents and visitors forever.

"We sincerely appreciate the Thompsons' commitment to conservation and look forward to working with them to maintain the ranch's agricultural and natural values," Ryan said in a media release.

Tim Thompson said his family has run the ranch for more than 100 years, and it is pleased with the easement agreement.

"Working with the Green River Valley Land Trust made sense financially," he said. "(It) allows us to leave a legacy we can be proud of."

He said the conserved property will continue to anchor the Thompson's cattle operations.

The easements are expected to preserve crucial wildlife habitat and migration routes for antelope, mule deer, moose and elk. It will also provide habitat for waterfowl, sage grouse and migrating songbirds.

The property includes a quarter-mile-long, 156-acre bridge for antelope to migrate to year-round habitat and nearly three miles of crucial migration corridors of big game.

About 10 miles of riparian habitat and aquatic systems along South Piney Creek, Middle Piney Creek and Beaver Creek will also be preserved under the agreement.

The Green River Valley Land Trust was awarded a $400,000 grant from the Wyoming Wildlife and Natural Resources Trust - the highest ever in the state - and secured other grants and gifts to fund the easement purchase.

Ryan said a variety of partners contributed to the project, including the Wyoming Game and Fish Commission, The Nature Conservancy, the Rocky Mountain Elk Foundation and the Jonah Interagency Mitigation and Reclamation Office.

The Jonah office established two conservation easements in May that will permanently protect about 2,600 acres on Freddie Botur's Cottonwood Ranches near Big Piney. The project marked the first use of the Jonah Interagency Office oil and gas mitigation funds for permanent land conservation.

The Green River Valley Land Trust is a private, nonprofit organization that works with Wyoming landowners to conserve the state's natural and agricultural resources.

Contact Jeff Gearino at 307-875-5359 or gearino@tribcsp.com.