the mountains there are really pretty and there is much stuff to do in the summer, also.
Breckenridge is located in Summit County, which has Copper Mountain, Keystone, Frisco and Lake Dillon. There are factory outlet stores at Silverthorne and many great restaurants and brewpubs. Last time I was up there, Copper Mountain ski area would let you take their chair lifts up to the top of the mountain for free, so that you could walk down at your own leisure. CM also had free paddle boats on their small lake. You can rent some bicycles and go on many different trails.
Breckenridge itself is a really cute little town done in the Victorian style. There are the usual movie theaters and other types of entertainment. There is no shortage of things to do.
I don't think that you would regret spending a week there, at least if you like the outdoors- hiking, biking, etc.
Being a travel agent in the past, I always recommend that you send away for the visitors guide from the city and/or the state. With this particular city, there may be something under the headline of Summit County, also- as that is where those major ski areas are all located.
http://www.rsn.com/cams/summithttp://www.gobreck.com/page.phphttp://www.gobreck.com/page.php?pname=summer/activities/summer-activities-breckenridgesome of the specific summer activities