Members of a federally appointed review panel will descend to the bottom of Henderson Mine today to get a first- hand look at one of the four sites being considered for a $300 million underground science lab.

Twelve members of the expert panel and four National Science Foundation officials are expected to tour the molybdenum mine near Empire, said Colorado School of Mines engineer Mark Kuchta.

Henderson is one of four sites trying to land the federal Deep Underground Science and Engineering Laboratory, known as DUSEL.

The other three finalist sites are in South Dakota, Minnesota and Washington state.

Members of the review panel visited Minnesota's Soudan Mine on Friday and South Dakota's Homestake Mine on Sunday, said University of Minnesota physicist Marvin Marshak. They are scheduled to tour the Washington location later this week, he said.

The visitors will spend eight hours at Henderson today, said Kuchta, a member of the team coordinating Colorado's proposal.

"For this visit, they were very clear that what they're really after are technical details about the site, and that's what we're going to be presenting," he said.

The visiting panel is expected to include mining engineers, electrical engineers, geotechnical engineers and underground-construction experts, Kuchta said.

Safety experts and environmental specialists may also be in the group, he said.

NSF officials refused to discuss details of the site visits, saying the review process is confidential.

This spring, the agency is expected to award the winning DUSEL team up to $15 million for three years of additional studies.

Funding to build the $300 million lab must be approved by Congress.

DUSEL would be used for forefront research in physics, microbiology and the geosciences.

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