Jackson Lake State Park

"Just 90 miles from Denver, in 2020 Jackson Lake State Park became the first state park in Colorado to be designated an International Dark Sky Park, fitting right in with the state's whopping nine official Dark Sky Places. It was already a go-to for amateur astronomers—with free astronomy meet-ups from July through September—but advocates recently removed street lamps, updated light fixtures, and obtained a Celetron telescope for public use. Stargazing is especially good from the sandy beaches around the massive reservoir, whose reflective surface mirrors the Milky Way."