After the Spanish arrived in the 16th century, the Huichols retreated into the rugged mountains of northern Jalisco and Nayarit. While nominally converted to Christianity in the colonial period by Franciscan missionaries, most of the native Huichol culture managed to survive intact due to the isolation, and because the area lacked mineral or other resources of interest to the Spanish. Mexican historian and anthropologist Fernando Benítez states that the Huichols have probably maintained their ancient belief systems better than any other indigenous group in Mexico. Much of this isolationist tendency remains intact although economic circumstances have forced a number of good Huichols to migrate to areas such as Guadalajara, and coastal areas to work or sell their wares.