In Dog Lake, depending on how much wind and rain there is during the summer, the thermalcline can be anywhere from 45 to 65 feet deep. The Lake Trout tend to stay right above the thermalcline as that's where the oxygen to coldest water ratio is at it's best. Generally with normal summer conditions the 50-foot depth is the magic spot for Lake Trout. They will stay in the 50-foot range but tend to stay close to drop-offs and structure because that's where the baitfish are. In the evening they do take short missions into shallower water if that's where the baitfish are. If you have a smaller motor like a 9.9hp or 15hp, all you need is your walleye or pike rod, a 3-way swivel, a 2 oz weight and a light shinny lure. You just tie two 2-foot lead lines from the 3-way swivel to the sinker and the lure. Get a troll going and slowly drop your line until it hits bottom in the 50-foot range and keep trolling. If you have a bigger motor like a 20 to 25-hp, you will have to back troll, as forward trolling would be too fast. With even bigger motors you would need to use downriggers, which are not near as fun as using a 3-way swivel.
Lake Trout can be a frustrating fish to fish for, which is why not too many people specifically target them. They turn on and off like a light switch. Daybreak to about 10:00 am, 1:00 pm to 4:00 pm and then later during the last 2 hours of light are the best times to catch Lake Trout. They also hit best on calm sunny days with high pressure.