You might want to contact the education department at the Crow Canyon
Archaeological Center in Cortez, Colorado. They do a wonderful job of involving
the public in archaeology, providing one day, three-day, and week-long programs
for school children and for adults. You can reach them at (303)565-4859. Also
the Passport in Time program initiated by the Forest Service allows the public
to participate in digs at National Forests throughout the United States. I
believe the PIT contact is Carol Ellick at (800) 281-9176 or (520)722-2716.
Good luck!
Andrea Clark