Mount Cornwall is in the Elbow Valley of the Kananaskis Range. By itself it presents about 1300m elevation gain and the approach is on a dirt road, so a mountain bike is advised. If doing a traverse of Banded Peak, Outlaw Peak, Mount Cornwall and Mount Glasgow, I recommend going from south to north, so you walk the longest section of road first, while still with a fresh mind and body. Two parties approaching on mountain bikes can go in opposite directions and swap bikes on return, making this a more reasonable one-day objective. Otherwise, a more leisurely two days are recommended to get the full experience.
The Glasgow group of four peaks is clearly recognisable from Calgary and the Trans-Canada highway due to Banded Peak's defining brown cliff band showing during winter months, and Cornwall's ever-snowy scree slopes during the summer. Being in the Front Ranges, they are in condition and free of snow much sooner than others.
Access is by Highway 66 west of Bragg Creek. Follow it all the way until the end and into the Little Elbow Recreation Area parking lot. Do not continue into the campground but turn left into the parking lot; you can leave a vehicle overnight here. There are restrooms here as well as an information board. The highway is closed at Elbow Falls from December 1 until May.
No permits are necessary for entering Kananaskis and day tripping. Inquire at the visitor centre about overnight permits. Bears frequent the area, so check for trail closures before you leave, and be bear-aware at all times, frequently making noise to avoid encounters. Some people like to carry bear spray.
Being in the Front Range, condition will vary significantly year to year. June through September is probably best. If planning on the full traverse, make sure some snow remains for a source of water, but drier conditions will be required for Glasgow - so do not hurry too much, depending on the year. This can all be seen from the highway or even from Calgary, making planning easy.
There is a large campground next to the parking lot, as well as several backcountry campgrounds nearby. Check with the visitor centre for booking.
Check the Kananaskis website for trail closures and information, or call one of the Kananaskis visitor centres.