What a productive birding experience! Do you know why warblers tend to congregate in that area? I enjoyed seeing your fine photographs. Thanks Patti!
Gayle
I don't know if there is anything special that makes the area particularly enticing for warblers. It's a "migrant trap" in general...
The birds, by the time they hit Lake Erie, have been flying over an agricultural desert for a long time; they hit the lakeshore, and decide to settle down and refuel for awhile before crossing the lake. In that way it's similar to many other well-known migrant traps where some natural obstruction or feature (mountains, like Hawk Mountain), bodies of water like Delaware Bay (Cape May, NJ), etc. causes migrants to stop or at least funnels them in a particular direction.
At the festival I attended a talk by Chris Wood, who works at the Cornell Lab or Ornithology as project leader for eBird (among many other credentials) on the current state of the science around bird migration. One of the things he pointed out is that birds have different migration paths to/from the neotropics; some cross the Gulf of Mexico and some fly around it, etc., and this area of northern Ohio is right where those paths converge for birds flying north to nest in Canada's boreal forests.
There is a narrow band of green space (state parks or wildlife areas, several national wildlife refuges, and privately run conservation areas) on the lakeshore that was preserved when the rest of what used to be called the "Great Black Swamp" was drained for agriculture. It's green, moist, and swarming with the bugs that migrants love to eat! The day that I managed to get the best photos was a day that it was also cold and windy, so the birds were feeding lower in the trees.