Memorial Day may be summer’s unofficial kickoff, but there’s nothing casual about the planning that goes into this weekend. From half-athletic, half-cultural events such as the Bolder Boulder to free, large-scale music festivals such as the Denver Day of Rock, celebrations abound along the Front Range. Of course, if all you want to do is watch a motorcycle parade or hear some patriotic music, you can do that, too. Here is a sampling of some of the biggest and best events along the Front Range for this three-day invitation to summer. Veterans Memorial Day Tribute When: May 26 Where: 1340 Sherman St.