A judge recently heard oral arguments in a lawsuit over the Federal Highway Administration’s proposal to build a freeway from southern Arizona to Kingman.

But conservationists say the project will harm wildlife habitat and cut off migration corridors.

One version of the project would parallel I-10 and would pass by national monuments, tribal communities and Bureau of Land Management areas.

Conservationists, government agencies and politicians have raised questions about it.

The suit says the government has sidestepped criticism by proceeding with the project without understanding its environmental impacts or even the exact route.

"So this whole linear highway project would be severing wildlife linkages the federal and local agencies have been working to protect for years," said Carolyn Campbell, of the Coalition for Sonoran Desert Protection.

Attorneys with the Highway Administration said that a number of the issues conservationists raised could be addressed later in the process and that the project lacks funding at this time.