Learning Expeditions, a program run by the Arizona State Museum, occasionally offers scholar-led archaeological tours. For information, contact the marketing department at the museum (tel. 520/626-8381).

For a look at a completely different sort of excavation, head 15 miles south of Tucson to the ASARCO Mineral Discovery Center, 1421 W. Pima Mine Rd., Sahuarita (tel. 520/625-7513), where you can tour a huge open-pit copper mine and learn about copper mining past and present. The center is open Tuesday through Saturday from 9am to 5pm; admission is free. November through April, 1-hour mine tours are offered five times a day. These tours cost $6 for adults, $5 for seniors, and $4 for children 5 to 12. To get here, drive south from Tucson on I-19 and take Exit 80. You might want to combine this tour with a visit to the nearby Titan Missile Museum.

Want to taste raw cactus, learn about cholla-extraction devices, and hold a live tarantula or snake? Call Sunshine Jeep Tours (tel. 520/742-1943), which has a two-person minimum and charges $130 for the first two people and then, after the minimum is met, charges $50 for adults, $35 for children 11 to 15, and $25 for children 6 to 10. On these tours, you'll head out across a private ranch northwest of Tucson and pass through some of the densest stands of saguaro cacti in the state.