You decide: look at the map here. The National Park Service wants to convert huge swaths of land surrounding various Los Angeles-area valleys into wildlife corridors to be administered by the NPS.

The "Rim of the Valley Corridor Study Act" - sponsored by Rep. Adam Schiff [D-CA] - would commission a study on this issue. Would the study be biased towards what the NPS wants?

More information on these plans here, here, and here.

See also 2/9/05's "Senate OKs study of Rim of the Valley":

A key U.S. Senate committee gave the go-ahead Wednesday to legislation that would allow the federal parks system to embrace a half-million new acres of mountains surrounding the San Fernando, La Crescenta, Santa Clarita, Simi and Conejo valleys.

Local officials hailed the Senate Energy and Natural Resources Committee passage of the Rim of the Valley bill, even as land rights organizations warned that local residents have been misled about the wide-ranging impact of the legislation.

The bill directs the Interior Department to study whether the so-called Rim of the Valley Corridor should be included as part of the Santa Monica Mountains National Recreation Area...

Also see 2/12/05's "Valley Rim plan opposed".

I note also the artificial-looking corridor running from Griffith Park to near downtown and then back up towards the San Gabriels. I'm sure there are many wolves, bears, and other furry critters who would make the mostly concrete-encased L.A. River part of their migration paths.