Early in the Book of Mormon, Lehi famously names a valley after his son Lemuel, and implores him:
10 ...O that thou mightest be like unto this valley, firm and steadfast, and immovable in keeping the commandments of the Lord! (1 Nephi 2)
Notice how Mormon describes a band of faithful Lamanites at a time of great wickedness just prior to Christ's arrival in the new world:
14 And thus there became a great inequality in all the land, insomuch that the church began to be broken up; yea, insomuch that in the thirtieth year the church was broken up in all the land save it were among a few of the Lamanites who were converted unto the true faith; and they would not depart from it, for they were firm, and steadfast, and immovable, willing with all diligence to keep the commandments of the Lord. (3 Nephi 6)