@wilma‘s link does not show a picture. This does
I summered in a high-intensity black fly hell in the Adirondacks for over 24 years. The ONLY method that works is the mesh body suit. I wore the top in late May and June in order to try to garden. It was extremely unpleasant.
Wearing it is very unsatisfactory, and if a few flies manage to slip inside, you have them buzzing around your mouth, ears and nostrils with no escape hatch. It is also hot and makes you sweat (which attracts even more bugs) and cuts down on visibly.
The sprays are noxious and not very successful.
Can you find another vacation spot? Spring skiing is fun.