Provo River Blue Winged Olive
March is almost here and that means the Provo River Blue Winged Olive (BWO) mayflies will be making an appearance. It’s a welcomed sign from Mother Nature that Winter is almost over. The BWO’s are the first mayflies of the year to hatch and also the last.
BWO’s are a greyish olive color with grey wings and two tails. They look like little grey sail boats floating on the river surface. You’ll start seeing them in good numbers mid March with peak hatches in early April.
They will kind of hatch all throughout the day but the main event is around 1pm. Depending on weather conditions it usually lasts a couple of hours. If you happen to be out on a cool wet day you could see an amazing hatch lasting for 3-4 hours. They love cold wet days.
The little olive mayfly hatches twice a year. There is a Spring and Fall hatch. They look identical as far as shape and color however their size is quite different. The Spring Blue Wings are size 16-18. The Fall fly is much smaller with sizes 22-24. Both are in the genus baetis which covers a wide range of Blue Winged Olive species.
The nymph starts off as an olive colored insect that turns black before emergence. Nymphing pre hatch can be so good you might not even want to fish a dry fly. With all of those nymphs drifting through the water before the actual hatch, trout will gorge without ever having to break the surface.
As with most insect hatches, trout will suspend mid column to pick off the drifting and emerging bugs before they reach the surface. When nymphing make sure to adjust your rig to ensure your flies are in the sweet spot of the river column. You could have the right bug on but have the wrong depth.
As they start to feed off of or just below the surface try fishing with a light weight emerger rig just under the surface. Swinging a soft hackle just inches below the surface to rising trout is another very effective technique. This is also a great time to fish a dry dropper rig.
When trying to match your fly to this insect make sure to get your size, shape and color as close as possible. Try to avoid bulky or over hackled flies.
You’ll have more success with a sparsely tied imitation. I like split tail no seeums tied in olives and greys. Also split tail comparaduns or sparkle emergent duns.
If you’ve never experienced a great BWO hatch check out this video. This video was taken during an October hatch on the Middle Provo River near Park City, Utah. Yes it was incredibly hard to not trade the camera for a fly rod.
Get out and experience some of the best fishing of the year. Both nymphing and dry fly fishing can be amazing during these hatches. Don’t let the Provo River Blue Winged Olive hatch pass you by. Contact Jeremy Allan Fly Fishing to book your Spring fishing trip for exceptional fishing.