I've kayaked all over southern and central Idaho. The one spot I keep coming back to is the same narrow waterway surrounded by truly unique, basalt rock formations, singing birds, and gently swirling blue waters.
The rock formations are fascinating, and the birds sing the entire time you are floating. The entire ride takes no more than an hour roundtrip, but I recommend you take your time.
The location is less than a mile from famous Balanced Rock, and it's the only park I've ever seen a rock chuck being roasted over an open fire at also.
We cooked some hotdogs and bratwurst Tuesday evening at about 6 p.m., played some cornhole, listened to some music for a bit and launched our kayaks with about two hours of daylight left.