The Mexican lakes have been famous for two decades among conventional bass anglers, but so far they have seen few fly fishers. The numbers of bass taken per day on spin and level-wind gear tell a story: They range from 40 to 90 fish weighing from 2 to 10 pounds or larger. But little information was available on the lake fly catches until the waters were explored by Keith Kaneko of Angling on the Fly, who has fished them repeatedly over the past three years with other expert fly anglers. I fished both lakes with Keith on an exploratory trip in January 2008.

Lakes El Salto and Mateos (650 miles south of Nogales, Texas) are man-made earth-dam lakes built in 1983 and 1967, in the foothills of the Sierra Madre Mountains in Sinaloa Province, near Mazatlán and Culiacán on the west coast of Mexico. Both were built for irrigation of the rich province lowlands and both held a native largemouth bass species to which the Florida strain of largemouth were added (Mateos in 1975 and El Salto in 1985) to feed on a rich forage base of tilapia and shad. Both lakes are gillnetted commercially for tilapia, but this controlled fishery does not seem to affect the largemouth that compete with and feed on the tilapia. Cropping the overproductive, and predacious, tilapia may actually improve the bass fishery.

Mateos
The lake (full name: Presa Adolfo López Mateos) 55 minutes by car from Culiacán has a full pool 50 miles long and 3 to 4 miles wide (55,000 acres), with an estimated 100 miles or more of shoreline and fertile bass and shorebird habitat, including clear water, drowned trees, hyacinth-choked coves, islands, shallows, submerged brush, rocky and gravelly shorelines and headlands, bluffs, islands, and flooded canyons.

In early January when the purple, yellow, and white Amapa trees flower along the rugged surrounding mountains, the lake has an aura of Taoist enchantment, especially in early morning and evening when the sunlight is soft and angular, the lake is quiet, bobcats prowl the shorelines, great blue herons stalk silently, and white pelican flocks sail overhead like animated clouds.

[Sinaloa province, with 13 rivers and 15 lakes, is called the "water capital" of dry Mexico. Lake Mateos is fed by the Tamazula and Humaya rivers. The Editor.]

Mateos is a reborn largemouth fishery. In the '80s and '90s its fishery, once known for fish over 10 pounds, crashed due to severe droughts and excessive drawdown for irrigation. But during the past three years, monsoonlike rains have refilled the lake and revived the fishery and Mateos is rapidly recovering its large-fish reputation.

Recent recorded catches of 8- to 10-pound bass confirm this. The lake largemouth record weighed over 16 pounds. In years past, a gear angler took 27 bass of 10 pounds or more in six days of fishing in May. Two were over 15 pounds.

Mateos is again a largemouth-producing factory, where large schools of shad and tilapia are attacked by bass and bait-feeding waterfowl. At bass spawning time (February and March) the large tilapia surround the bass spawning nests and dash in repeatedly to devour the eggs. This is the predator/prey relationship that contributes to the Mateos fisheries balance. The gillnetting may actually help to control tilapia predation on the bass.

Ironically, both Mateos and El Salto lakes have floating gillnets in virtually every cove--so many of them that first-time bass fishers wonder how the bass can survive. They obviously do and in surprising numbers, sizes, and fighting energy. Expectations on a normal day of fishing (fishing daylight to 11:30 A.M., lunch/siesta, then fishing again 1 to 5 P.M.) include: 40 to 75 largemouth hooked on conventional gear and 10 to 30 on fly.