Medford, OR -

The Congress is again considering legislation to expand the Oregon Caves National Monument nearly tenfold.

The Medford Mail Tribune ( ) reports the U.S. Senate passed the measure unanimously on Wednesday, sending it to the U.S. House. A similar bill failed in 2009.

The monument now covers 488 acres in southwestern Josephine County.

The new legislation would transfer 4,000 acres from the U.S. Forest Service to the U.S. Parks Service.

Supporters say the expansion would improve forest health because the Parks Service has more money for forest restoration.

Logging and other operations allowed on Forest Service lands are banned on Park Service holdings. Recreational access to hunters and others would still be allowed.

The bill also calls for scenic river designation for the underground River Styx that travels through the caves.