Formed by glacial activity over 10,000 years ago, Last Mountain Lake’s southern tip is about 45 kilometres northwest of Regina, at Craven, in the Qu’Appelle Valley. Originally known as Long Lake, the lake was renamed in 1974 based on a Plains Cree legend about the Great Spirit shoveling dirt from the valley the lake now occupies. The legend described that the dirt then formed the Last Mountain Hills, east of Duval. The lake averages 1.5 kilometres in width and spans west and north for over 90 kilometres. The depth of the lake varies and ranges from about 40 feet at the widest part, to nearly 100 feet in the narrower valley wall area. Last Mountain Lake is the largest naturally occurring body of water in southern Saskatchewan.

Throughout the late 1800s and early 1900s, the lake was a busy trading area with the formation of Regina Beach (around 1880), as one of western Canada’s oldest lake destinations. After that, numerous lake resorts sprouted up along the south end of the lake, being close to the growing communities of Regina and Moose Jaw. Last Mountain House Provincial Park, located on the southeast shore, includes historical Last Mountain House, which was built by the Hudson's Bay Company in 1869 and used as a trading post until 1871. The Post competed with the increasing number of independent traders who had followed the buffalo that had moved into the area. The buffalo soon moved on and some time after the second season, the Hudson’s Bay Trading Post was completely destroyed by fire. The site has been an important archaeological location and some of the original buildings were reconstructed in the 1970s to serve as an educational tourist attraction.

There are several other resort areas located along the southeast and west shores of the lake with the densest development at the very southern end. Historic access to the area was opened up by the Saskatchewan Railroad and Steamboat Company who operated a rail line along the shore and also operated steamships on the lake. The steamships brought tourists north to the community of Arlington Beach, which became known as a popular spa style getaway with a cozy hotel and lots of swimming, fishing and boating activities. In the 1940s, Arlington Beach began its life as a church operated facility.

The northern tip of Last Mountain Lake is home to the Last Mountain Bird Observatory. Reserved by the Canadian government in 1887 as a natural wildlife area, it is the first federal bird sanctuary reserve in all of North America. The sanctuary was designated a National Historic Site of Canada in 1987, its 100th anniversary. Today, the Last Mountain Lake National Wildlife area encompasses over 2,500 acres and continues to be registered as a wetland of international importance. This area is known as a migratory stop for over 280 species of birds and a breeding ground for as many as 100 different species, including endangered species such as the peregrine falcon, the Cooper’s hawk, the burrowing owl and the whooping crane. The southern boundary of the reserve is located approximately 8 kilometres north of Sunset Acres Resort.

A number of park areas are located along the shores of Last Mountain Lake including Rowan's Ravine Provincial Park, the Regina Beach Provincial Recreation Site, Etter’s Beach Provincial Recreation Site and the Last Mountain Regional Park. Each offers recreation seekers different getaway opportunities.

About thirty minutes south of Sunset Acres Resort, Rowan’s Ravine offers a full-service marina and campground, a restaurant, mini-golf, and other facilities. Rowan’s has historically held a large fishing tournament every Fall. Last Mountain Lake contains various fish species including walleye, yellow perch, northern pike, whitefish and others. The lake is best known for walleye and pike and is also considered among the best top ten in Canada for ice fishing. Other popular activities around, and on the lake include, camping, hunting, sailing, boating and skiing. Besides ice fishing, winter activities include cross-country skiing, skating and snowmobiling.