Utah in May

So we bought some plane tickets last night. We’d been debating heading to Japan for Cherry Blossoms this spring but we ended up with really great tickets to Vegas instead so we’re going to Zion and the Grand Canyon at the end of April and early May. My family will fly back and I will stay to fish and backpack for another 10 days. I’m keen to explore anywhere in Utah. Not sure what May is like for Fishing. I’ve only fished the Provo in June during the 2015 Oni school. SO…I’m asking for recommendations for Tenkara friendly waters between Vegas and SLC that will be fishable in May Any suggestions in Zion? Any suggestions or recommendations around Boulder/Escalante? Best guidebook for Utah? Really interested in Bonneville Cuthroats. If anyone wants to meet up to fish in Utah between May 6-15, let me know.