Best place to look for insects in the United States?
I've been avidly observing and photographing insects for six years now in the New York City area and occasionally in the Sarasota, Florida area. I have a general appreciation for all insects with a particular interest in hymenopterans minus ants. I'm planning to take a short (3-4 days) trip to an area (within the contiguous United States) where I have a good chance of seeing a lot of insects that I can't hope to see around NYC and Florida, but I don't know where I should go. I won't likely be able to afford more than one or two such trips in my lifetime, so I want to choose carefully.
Can anyone recommend an excellent spot to look for insects in the contiguous United States, not close to Florida or NYC? In researching insects on the Web, I often come across interesting insects that occur in California that either don't occur elsewhere or at least don't occur in the eastern United States. So I have a hunch that California is where I need to go. But even if that's true? Where in California should I go?
Does anyone have a recommendation for a location (with a best time of year)? I'm hoping for something specific. So rather than something like, "I recommend Idaho," I'm hoping for something like "I recommend the such-and-such state park of Idaho in July."