The Jackson County Board of Commissioners will hold its own public hearing on the proposed expansion of the Cascade-Siskiyou National Monument after an earlier meeting called by U.S. Sen. Jeff Merkley, D-Ore., attracted mostly expansion supporters.

The commissioners' hearing is at 6 p.m. Thursday in the North Medford High School Commons, 1900 Keene Way Drive, Medford.

Merkley and fellow Democratic Senator Ron Wyden have proposed doubling the size of the 66,000-acre monument east of Ashland, which was created in 2000 by President Bill Clinton to protect the area's biodiversity.

"We need to make sure we send input back to Washington, D.C. that reflects the true opinions of all those that live here," said Jackson County Board of Commissioners Chairman Rick Dyer. "We want to hear from ranchers, recreational groups, hunters, environmental groups, hikers, the tourism and timber industries and everyone else that this decision affects."

At the previous meeting held at Southern Oregon University in Ashland, expansion opponents were outnumbered by supporters, many of whom wore blue "Oregon is Monumental" T-shirts.

Supporters of an expansion say it will further protect biodiversity, watersheds, Jenny Creek's headwaters and high-elevation public lands needed as a refuge by animals and plants as the climate changes.

Supporters hope Interior Secretary Sally Jewell will urge President Barack Obama to use the same powers under the Antiquities Act to expand the monument that President Clinton used to create it.

Opponents worry about taking more federal timber lands out of production, increased wildfire risk and the loss of ranchers' grazing rights.

County commissioners said they will take input they receive at Thursday's hearing and forward it to Jewell in hopes she will share it with Obama before he makes a decision.

"We look forward to hearing from the citizens of Southern Oregon regarding this expansion," said Commissioner Colleen Roberts. "The outcome of this decision will have dramatic long-term effects on our communities."

— Reach staff reporter Vickie Aldous at 541-776-4486 or valdous@mailtribune.com. Follow her at www.twitter.com/VickieAldous.