The RS-2
The RS-2 was developed by Rim Chung (the "R" in RS-2, I've forgotten
what the "S" stood for), a Denver area tier and fisherman of note.
It was developed as a general purpose fly to handle the various mayfly and
midge hatches on the South Platte. As such, it has evolved into a fly style
more so than a single pattern, with the wing style its signature, and you
will see it tied in various colors at the many shops servicing the South
Platte area of Colorado. The standard RS-2 as tied by Rim Chung has split
tails, a dubbed body of beaver, a tuft of the fluff at the base of a hackle
for a wing and will have a grey color overall. The RS-2s found in the fly
shops will usually not have split tails and usually use any fur for the
dubbing. The grey RS-2s are called simply "RS-2s" whereas any
other color will be referred to as a "(whatever color) RS-2".
Rim ties them in different sizes and colors as well. The fact that this
is the only fly he carries on the stream with him speaks to its versatility.
Tying the Olive RS-2
The olive RS-2 (as I have tied it) is as follows:
Thread: Camel 8/0
Tail: Dun Hackle Fibers (sparse)
Abdomen: Hareline #39 Dark Olive Brown
Wing: Black Marabou
Thorax: Same as Abdomen
For this imitation of the small baetis nymphs, everyone recommends dubbing
as sparsely as possible. If you were using RS-2s to imitate other species
of nymphs, dub such that the body is of appropriate thickness. After tying
in the tail, the abdomen is tied tapering forward to about the 3/4 point.
The wing (6-8 fibers of marabou for a #20 Tiemco 100 hook) is then tied
in and the thorax is dubbed over where the wing is tied up to as close to
the eye as possible. The fly is then whip finished (it won't really have
a "head" per se) and then the wing is trimmed to a point about
midshank.
As I said, you will see this fly with split tails. You will also see it
where the thorax is dubbed and then the wing is tied on and a true head
is tied. Most people agree (note that I said "most") that these
variations don't affect the fishing success. Another option for the wing
is CDC, which makes an effective emerger. Also, a curious thing about this
fly as I have tied it is that RS-2s with black wings are extremely effective
during the baetis season, but only so-so the rest of the year, whereas an
olive RS-2 with a grey wing is much more effective in the off-(baetis)season.
It is speculated that the fish key on the black wing pads of mature nymphs
while they are hatching. In the dead of winter, a grey wing may make the
pattern look more like a midge pupa. Since, as I mentioned, this is more
a fly style than a fly pattern, its applicability to different bugs (PMDs
vs. BWOs vs. midges, etc.) and stages (pupa vs.nymph vs. emerger) is only
limited by your imagination.
Fishing the RS-2
The olive RS-2 in the appropiate sizes is an effective fly year round on
the South Platte. The large population of baetis no doubt accounts for its
effectiveness, although its also effective during midge hatches during the
dead of winter. Even though often thought of as an emerger, I mostly fish
this pattern with deepdead drift nymphing techniques, usually in a two-nymph
rig. The other nymph is usually a larger fly, but sometimes when I know
the baetis are the ticket I will fish two RS-2s which are slightly different
(i.e. grey wing vs. black wing, ribbed with black thread vs. not). Then
as the hatch progresses, you can switch to fishing this fly as an emerger,
either by greasing the marabou tuft or switching to a fly tied with CDC.
Once again, use your imagination.
Dan Snow (SNOWDE@FAFB.AF.MIL)