Lake El Salto is a 24,000-acre irrigation reservoir just north of Mazatlan. During construction on the dam at El Salto in the mid 1980s, the Mexican government stocked the partially formed lake with tilapia to provide a small commercial fishery for local residents. At about the same time, seeing a big lake with a newly made forage base, an American outfitter named Billy Chapman stocked the lake with Florida-strain largemouths. With lots of food, a long growing season, and few predators, the bass prospered along with the fishing. After the dam was finished in 1989, Billy Chapman Jr. opened Anglers Inn (anglersinn.com) on El Salto's shoreline, where I was a guest. Chapman wisely made catch-and-release fishing a lodge rule to keep the bass growing and the fishermen coming back. As I learned while fishing with Chapman's guides, just about all the bass lures--particularly large plastic worms and jigs--that are common on bass lakes farther north also catch these lunkers. But it was one guide, Martin, who pulled a soft-plastic swimbait from my bag and said, "Big fish. This is the best."