After a recent divorce, Mackenzie Granger opens her summer camp, Camp Little Otter, and tries to run it on her own. Financial struggles cause her to consider a buyout offer from Roger Shepard, owner of Camp Ridgefield, the resort across the lake. Mack's son, Buzz, is a counselor-in-training and promises a successful summer. Handyman Cole helps out, but appears interested in Mack more than her camp. Lead counselors Robbie Matthews and Sarah Brennen continue their annual summer romance.

Mack announces the annual "capture the flag" competition. Her ex-husband Steve arrives, looking for a place to stay for a while and she lets him stay and help. Robbie must assist his mother with her troublesome gambling.

Little Otter prepares for its mixer dance with Camp Ridgefield. Buzz thinks his deejaying the event will improve his reputation with the ladies. Mack hears about a guest family switching to the more-modernized Ridgefield and ponders installing a cell tower.

It's Valentine's Day in July, with Valentine-grams and a carnival. Mack must give Roger a private tour of Little Otter, when he wins a raffle. On the tour, they argue, flirt, and eventually succumb to their mutual attraction.

Camp Little Otter gets a record-breaking heat wave and everyone tries their best to keep cool. Buzz's 16th birthday is drawing near and he plans the greatest party the camp has ever seen in his cabin, or so he thinks. Sarah goes to Camp Ridgefield to borrow a generator and she meets her secret crush, Miguel Santos. Mack is surprised when her ex-husband gives Buzz the night vision goggles she had planned to give him for his birthday. Cole must help her come up a more-perfect birthday gift.

It's the annual CIT Parents' Weekend. Mack must deal with Zoe's high maintenance mother and Buzz, who doesn't like her punishment for his drinking on his birthday. Roger inadvertently reveals Sarah's secret affair with Miguel. Kip has a health scare, revealing to the group that he has cancer.

When a local official begins issuing marriage licenses to same-sex couples, Mack hosts a wedding for Raffi and Todd at the camp after Grace convinces them to get married there. Roger throws a bachelor party, hoping to attract more gay people to his Ridgefield camp. Kip overcomes his health scare and dumps Chloe, in order to show his true affection to Marina. The governor voids the issued licenses but Raffi and Todd have the ceremony anyway. At the wedding party, Cole makes a move on Mack.

Mack worries about her parents' visit for the Harvest Moon Festival. Mack's dad decides to start a prank war against Camp Ridgefield. Kip helps Marina when she has a pregnancy scare. Robbie learns Sarah is working for Roger.

The CITs (counselors-in-training) get ready to spend a night on Bear Mountain. Kip and Marina decide to go public with their relationship. Robbie goes on a journey with French backpackers. Mack learns Cole is thinking about leaving to work for Roger.

Kip and Marina spend the night together on a blanket in the woods. Buzz and Grace become boyfriend and girlfriend, even though she claims nothing sexual will occur between them. Sarah and Robbie nearly reconcile but remain apart. Cole is Mack's choice from the love triangle, but he decides to take the Alaska job. Marina is in Mack's backseat when she closes the camp and Buzz promises Kip that he will keep an eye on her during the coming school next year.