A few Importnat items. Sebego Lake SP does Not allow pets. I suggeat looking for a care taker fir your dog  It specifically tells you this when you try to reserve a campsite . the Day use area does allow dogs . leashed . 

The lake was created by a glacier , but it certainly is Not Glacial . last years swimmimg temps were in the 60s and low 70s

You can check temps at PWD. 

The state park has very few campsites with Hook Ups . ie electric and water and you will pay more .

Please do Not feed the ducks 

Keep,your trash collected and place in dumpster or your vehicle at night .,if not , you will be cleaning up racoon spotted trash in the morning. 

It is a quiet Family campground. You won't find a kids program, arcade, or swiiming pool there . loud partiers are frowned upon .

I have been camping there for 54 years and have never missed a summer