Mack fishing should start picking up right about now, they are all rested from their spawn and should be getting hungry again and back to their agressive ways.
I would fish for them kind of shallow still and stay shallow untell late May. Shortly after ice-out their eggs will rise to the surface and get a little bit of oxygen hatch. Then they will try to escape into the shallows for protection. While escaping they will be preyed apon by all preditory fish including the Mackinaws.
Sometimes during cold weather months and especially during the spawn they can be found in relatively shallow water, up near the surface and in close to shorelines.
That's why you don't always have to fish deep for them under the ice.
If you fish for them in the summer, you know they tend to hug the bottom or suspend over deep water, where downrigger trolling and deep jigging is effective. Use light weight line to reduce friction for easier depth trolling.
If you are going to fish for them deep look for rock humps or steep drop offs and ledges 30-60 feet deep, and when I say shallow I mean for macks, 20 feet deep or so close to shorelines.
Although their metabolisms may be slowed by really cold water temperatures in February, winter lakers are often cruising fish, and they can be readily attracted by a properly jigged bait.
One of the true fail-safe standbys of winter Mackinaw fishing is jigging leadhead tube baits (usually white ones) with strips of sucker meat or nightcrawlers, I use whole suckers.
As for Lakes in Colorado with the best Lake Trout fishing here are my favorites and Contact info for updates:
Taylor Park Reservoir - Gene Taylor's Sporting Goods (970-641-1845) in Gunnison.
Williams Fork - Denver Water Dept. For more information, call (303) 628-6526.
Granby and Shadow Mountain lakes - Budget Tackle (970-887-9344).
Blue Mesa - Also Gene Taylor's Sporting Goods.
Twin Lakes Reservoir - The Granite General Store (719-486-1679).
Turquoise Lake - Buckhorn Sporting Goods (719-486-3944) in Leadville.
(Blue Mesa holds the State Record)
Hoped my ramblings help you some.
