I would say the majority of people heading into Kananskis are looking for a scenic drive and a picnic or camping.
Picnic areas are located all over the park called "Day Use Areas". The most popular and pretty locations are Barrier Lake and Upper Kananaskis Lake. Especially on a beautiful summer weekend, go early to stake out your table, I would say by 11:00 am at the latest. Bring firewood to roast your hotdogs.
Firewood is available usually at gas stations, or in Calgary. Also, bring lawn chairs, so you can sit down by the lake. The picnic tables/pits are usually located higher up , away from the lake.
Stop by an Information Centre if you have any questions regarding Day Use Areas.
Every weekend in the summer, hundreds of people flock to Kananaskis to go camping. The Victoria Day Long Weekend (around the 3rd week in May) is the traditional "opener" for camping. Even though most of the time people freeze to death or get snowed on, they still go. I think the May long weekend in 2003, was nice though, but this is pretty rare.
The campsites range from cushy -- Mt. Kidd has a hot tub and general store to backcountry primitive. Most campsites need to be reserved; if they are first come, first served, people may head out Thursday evening or Friday to stake the best sites.
For more on camping, go to the website below ; click on camping infomation under Hot Links. The info listed will have links to who manages what campgrounds.