All streams except the Firehole River are in top fishing condition. Terrestrial patterns will be effective on all, especially when hoppers kick in soon. For now your best choice of when to fish would be the more humid, thundershower threatening days. These offer more overhead cover than bright days, and humid conditions bring on delayed hatches. Beware of the growing horse fly and deer fly populations (but they make humpy variations very effective!), but be happy that mosquitoes are beginning to diminish. If you have not seen our Yellowstone Park small stream discussion posted on July 19th, take a look because there are some gems within!