Big flat beaches in early season before they raise the lake level. Rocky (Gorge style) launch in mid to late summer. Stay upwind or have boat support, downwinders are possible with a car pickup.
Summer weather ranges from rather cold to very warm (changes quickly). The water never gets that warm, 40°F-65°F in summer, Frozen in winter. Spring suit or full suit all summer. Kitesurfing from May to September. Snowkite from January to March.
From Kalispell (Montana) take the 2 westwards towards Libby. In Libby take the 37 East/North towards Ripley, Jennings and Yarnell until you see the lake. Find a beach and launch from there.
Watch out for fisherman - good fishing for landlocked salmon and small trout. Great rock climbing, whitewater boating nearby. OK mountain biking. Watch out for bears Black and Grizzly. Good camping spot, there is only a small crew of kiters here usually no one to help launch/land so bring your own group. Lots of campsites on both sides of lake, some have bathrooms/developed parking some are just a fire pit.