For centuries, the Pima and Maricopa Indians have been farmers, harvesting rows of melons, potatoes and Pima cotton that run through the patchwork of dusty Arizona desert like emerald threads.

But today, as the suburbs of America's seventh-largest city push up against tribal land, the Pima and Maricopa are finding that the most valuable yield they can take from their land is not crops. It is Wal-Marts and Wendy's.In a trend increasingly common on Indian reservations across the country, commercial development is becoming a popular way to diversify tribal economies. Faced with declining federal revenues and uncertainty over the sustainability of gambling, a growing number of tribes are turning to more traditional industrial and commercial initiatives to boost long-moribund living standards.

While many native Americans claim that economic development is endangering Indian culture and widening the gap between rich and poor, a number of tribes have found that attracting private investment can be an answer to many economic challenges.

- The Mississippi Band of the Choctaw Indians has more than 5,000 employees - making it one of the state's 10 largest employers. Tribal businesses include electronics and manufacturing enterprises that serve Ford, Chrysler and Xerox.

- The country's largest tribe, the Navajo, whose land includes parts of Arizona, Utah and New Mexico, is developing resort areas and establishing tribal enterprise zones aimed at attracting businesses with tax and tariff incentives.

For their part, the Pima and Maricopa have a Wal-Mart retail center, a Wendy's fast-food restaurant and the Scottsdale Pavilions, a 140-acre retail center that is the largest commercial development ever built on Indian land.

But the expansion doesn't please everyone on the reservation. Although development has brought much-needed money to many Indian tribes, critics charge that it could increasingly bring tribes into an Anglo business world and accelerate the demise of native Americans' unique heritage.

"Some of the issues are the loss of farmland and a way of life for hundreds of years," says Nona Baheshone, director of community development for the Salt River Indian community - home of the Pima and Maricopa. "People are concerned about how development will impact their lives."

In addition, it's not yet certain that the money from this project will make it to all of the community. Tribal members who own allotment lands along the freeway corridor have built stunning homes as the result of deals with developers, yet about 500 families have been on a waiting list for years to get suitable housing.

But tribal members also realize that to replace decreasing federal dollars the tribal government must find ways to provide services, and that can be difficult to do - especially for tribes in remote areas.

Forrest Cuch, director of economic development for Utah's Division of Indian Affairs, says it takes a certain level of sophistication to succeed in business, and the poor education afforded many Indian children does not prepare them.

"We assume people are prepared to operate businesses, but they're not," he says.

But for those tribes that do succeed in business, the issue then becomes finding a way to balance economic prosperity with cultural preservation.

Some see the prosperity as a means to shore up cultural resources. The Fort McDowell community of Yavapai Indians near Phoenix has used part of its wealth to strengthen cultural and language programs. A video documentary and Yavapai dictionary are two of the projects in the works.