Lake McDonald, the largest lake in the park, is the major hub of activity on the west side. Carved out by massive glaciers thousands of years ago, the valley is home to the rustic Lake McDonald Lodge – one of the park's most popular accommodations – and several historic chalets. The area offers an array of activities including bus tours, boat tours, horseback riding, ranger presentations and access to two of the park's popular day hikes, the Avalanche Lake Trail and Trail of the Cedars. The lodge offers numerous dining options in a hunting lodge setting, complete with a roaring fireplace in the lobby. The lodge opens in late May and closes in late September and advance reservations are highly recommended. Tours and activities, as well as the park's free shuttle service, operate on the same schedule. There are also several campgrounds situated around Lake McDonald, as well as the Apgar Visitor Center. Reserve online in advance of your visit.

Recent visitors loved this crystal clear lake and many commented on its rainbow-colored rocks, advising that the shore on the west end was the nicest. Some suggested visiting in early May to avoid crowds and save money on the park entrance fee, but noted that roads, shops and restaurants are closed until later in the month. Lodge guests loved the rustic ambiance and peaceful location, but some bemoaned the limited parking and lack of televisions. However, animal lovers noted that this is one of the few areas in the park where pets are welcome. To learn more about the facilities at Lake McDonald, visit the NPS website.