Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.
Another thing to consider is that there was a Grayling sub-species specific to Michigan, which can no longer be collected for stocking efforts. Montana still had some of the sub-species specific to the region to collect and rear in a hatchery for the stocking. Technically, Michigan will never get back what it once had, even if the program is successful.