I saw the summer's first turkey vulture today along the interstate between Big Timber and Livingston. They disappear in the fall and return in the early summer when the ground is warming up enough to produce the thermals they soar on. They are beautiful to watch, tilting gently as they spiral higher and higher.
A less welcome omen of summer is the first mosquito of the year, also seen - or felt - today. The moisture that has encouraged the mosquitoes to hatch has also created a green explosion at our house; after being gone for just two days, we came home to aspens leafed out, lilies of the valley suddenly full height and filling out, bleeding hearts setting flowers, rhubarb leaves unfolding, peonies nearly full height, and chives flowering. My son mowed the lawn last Thursday, and it already looks like he hasn't touched it - after only three days. Weeks of cool, wet weather combined with two days of nearly 90-degree weather to provoke a sudden, massive irruption of summer.