Twin Lakes has good lake trout fishing, with some big ones still left. Like everywhere, most are still 15- 20", but there are a few 10 - 20 pounders and the rare bigger one.
Best way to mack fish is to jig with a 3" white tube on a 3/4 ounce jighead. Always tip with a postage stamp sized piece of sucker or anchovy. Carp meat is great too.
Fish in 25 - 50 feet of water. Another good method for mack fishing is slow trolling a 3 - 5" flatfish or countdown rapala.
For trolling deep well, you do need leadcore line or a downrigger. But this works well.
The key for macks is to start just before the sun comes up. Mornings are always best, and afternoons can be good if it is cloudy. Sunny weather seems to drive macks deep and inactive. Good areas are near drop offs or large flats. On twin, the area near where the two lakes connect is good. Just be sure your fishing in deeper water, but not too deep.
I was up there a week ago Sunday and did really well along the shoreline for stocker rainbows. My daughter and I used a bubble and light tan hendrickson dry fly. ( But i suspect any little tan fly would've worked.) No particular place, we just looked for rising fish next to the shoreline as we trolled. They were in several places.
We didn't get any lakers, but we didn't try real hard either.