The Gibbon, Firehole, and Madison Rivers are still the best places to focus your efforts in the Park these days. Conditions have been ideal to produce daily hatches of PMD and Baetis Mayflies on all three of these fun and unique waters. Stoneflies and caddisflies are also plentiful when the sun come out and warms things up.
On calm, sunny mornings we’ve seen good spinner falls on the Madison and Firehole Rivers. Cloudy afternoons have been best for emerging mayflies, and on warm evenings Nectopsyche and Hydropsyche caddis hatches are thick.
While many of the Parks other notable fisheries like Slough Creek, the Lamar River, and the Yellowstone River remain high and off color, many of the lakes are a great option for early season action with fish cruising close to shore. You can explore lakes like Yellowstone, Shoshone, Lewis, or Grebe with chironomids fished on a floating line, or leeches and buggers stripped slowly on intermediate sinking lines.
Rivers like the Gallatin (in YNP) and Gardner are beginning to come down, and clarity is improving, but temps are still very cold. These two fun fisheries will most likely be the next additions to the hit list in YNP, but it’s probably going to take another week or two for water conditions to improve, and bug activity to increase.