Hey James, good question. Unfortunately May and June tend to still be way too snowy in the PNW mountains for typical 3-season backpacking. On years with very low snowpack and warm spring temps things can sometimes open in late June or early July, but that’s usually a best case scenario. So, I’d recommend looking into low elevation trip possibilities or something on the coast, unless you have extensive winter backpacking gear/skills/experience. Hope that helps!