Re: small mouth flys for murky river?
Hey flyfisher it sounds like you and your cousin are doing well with the leeches and buggers.
Some things you might want to try;
Colors- black, chartreuse and white are the most visible colors in murky water
Flash- can draw attention by reflecting light
Go big- fish in murky water aren't usually as spooky as they are in clear water so you can often get away with bigger flies and heavier tippet
Flies that push water- fish can also zero in on bait by using their lateral lines to sense vibrations in the water. Stuff like muddlers with spun deer hair heads and flies that have materials like marabou, rabbit strips, streamers with wound hackle that "breathes" we you strip them (like buggers).
Flies that have built in action like Dahlberg Divers that you can bloop along the surface or make them dive a bit on retreive, or have an erratic up and down motion when retreived like clousers.
You might want to look through your fly box to see if you have stuff that combines some of these traits.
If the water is fast and murky due to run off, you might want some heavily weighted versions (with wire wraps, beads or coneheads etc) to get down, or a sink tip, or put a split shot a head of the fly (it can be a pain to cast great though). Look for fish to be out of the main current if the stream is really roaring. Along banks, in deeper water along the bottom in sections with big rocks that break up the flow, deep in quieter pools, insides of bends where the bottom starts to drop might be good places to try. You probably have some stuff in your box like these:
black buggers in larger sizes like 6 and 4
chartreuse or white clousers with flash
flies like Zonkers tied with rabbit strips in black, white, chartreuse or purple
black, white, or yellow marabou muddler
Flash Dancer (basically a muddler with a spun deer hair head, marabou tail and gold flashabou wing) and flies like Lambster suggested.
Anything big like a bucktail, deceiver, marabou, feather wing streamer or whatever 2 1/2"-3" long or bigger if you can throw it.
In slower water, lighter weighted versions of those flies would be good choices as well as stuff like:
poppers (would be fun to try, they make enough commotion that fish could find them)
Black white yellow or chartreuse Dahlberg diver
Hope this helps. Good luck.