I’ll tell you what is holding up…. the Upper Lake at Hosmer. Water temps holding at 59 to 61F, happy brook trout with the occasional nice rainbow mixed in and every once in a while a cutty to the net looks good. 
I fished there twice this week, and the indicator work was steady with Red Holographic Jigs, Zebra Midges and my Callibaetis Cate Jig. What was best though was a Hover Line stripping a callibaetis nymph! 
Some callibaetis hatching about lunchtime, and fish are looking to eat dries. Timberline Emerger, Gray Sparkle Dun and Harrops Captive Dun were the best for us. At times fish are feeding aggressively on Adult Damsels. Damsel Nymphs are important too. 
The Lower Lake was seeing water temps at 72 and is a no go for safe C&R fishing. 
BTW, I saw a brook trout in the channel swim under the boat that had a silver Mepps Spinner hanging from its lip. WTF?
Check out our flies we were catching a lot of fish on at Hosmer. Looks so real the damsels wanted to eat them too.