With opening day on most trout waters beginning Saturday 4/22 maybe a little pressure will come off the Fall River? Who knows for sure, as it is also Free Fishing Weekend in Oregon, so they might come out of the woodwork.
There have been good BWO hatches in the afternoon from about 11 to 2. You are likely to see some March Browns, Midges and Small Dark Caddis that could very well bring fish to the dry fly too.
Good nymphing throughout the day. Zebra Midges and Micro Mayflies off the back of an egg or rubber legs is a really good set up, and with ODFW on their 2nd stocking this week the hatchery fish are usually attracted to the Pink Rufus (ideally fished on a sink tip).