This emerger has become a fly that I have turned to after the Bob Quigley Emerger has been refused. This pattern is better in soft water and runs. The March Brown Hatch is from March - May on the Yuba. But, they are available to the fish all year long. We fish these on long 15 foot leaders to 5x tippet material. I treat this fly with Loon's Top Ride and then treat it during I fish it with Loon's Lochsa.