Ancient Native American artifacts likely are buried under the path of the proposed South Mountain Freeway, Phoenix's lead archaeologist and freeway planners agree.

But unlike the now-U.S. 60 built in the early 1970s, construction crews won't be allowed to encase the ruins in asphalt. "That's an old saw," said Todd Bostwick, who has studied the Hohokam people for more than 25 years. "They (crews) have to dig them now."