The Hot Head Pine Squirrel Leech is one of our favorite flies for the North Platte River near Casper, Wyoming. I wouldn't be without a few of these on any trip to Grey Reef - I almost always use them as a lead fly, no matter the time of year. They're a little sassier than the standard Pine Squirrel Leech, which I think is an advantage at times. These also work great as a nymph on our streams here in the Black Hills!