mn,
made a lot of bows from both species (Northern Michigan) the red elm/ slippery elm etc. is very good bow wood.....tough and elastic, and so is the grey elm (american elm). from my experience the edge goes to the slippery elm, but will not hesitate to use the grey if no red is available. They are both very good......there is also the ironwood (not musclewood), but the hop-hornbeam which is second to none. Ya probably got that in yer neck of the woods as well.
rich