BLACK KRYSTAL FLASH MIDGE
Best in tiny sizes (22–26), its black segmented body makes it a popular midge pattern. “This fly is just a great representation of the natural insects,” Chavez says.
FOAM WING EMERGER
Effective in both chocolate and gray, the fly’s ribbed patterns with short tails and tiny foam wings imitate a mayfly in the transition from nymph to adult. Baetis mayflies, or blue-winged olive to anglers, “are predominant in the San Juan River,” Chavez says.
BLACK WOOLLY BUGGER
The fuzzy fly suggests many foods that trout eat. “Because a Woolly Bugger imitates things that are moving and crawling in the water, the drift doesn’t have to be perfect,” Chavez says. “It’s a very forgiving fly.”
ADAMS
Usually tied with a gray body and a brown tail, this versatile dry fly (try sizes 20–26) imitates Baetis mayflies in the larger sizes and midges in smaller sizes. The Parachute Adams, a variation on the classic, has a white post at the top for visibility. “It helps you see the fly,” Chavez says. “With dry flies on the San Juan, it’s critical that they drift correctly.”
SAN JUAN WORM
Fished along the bottom, this gummy fly imitates aquatic worms in the river. “That’s a fly that originated here,” Chavez says. “People now use it all over the country.”