Rivers continue to be a good choice right now, especially the upper Eagle, Blue from Dillon to Green Mountain Reservoir, South Platte, both above and below Elevenmile Reservoir and the Colorado in the Glenwood area. Anglers need to keep in mind that a few days of warm weather or a spring storm can quickly discolor the waters.
Tail waters such as the Blue River below Dillon and the South Platte are very low and clear. Anglers should consider fishing light tippets and small flies. However, those are what most anglers are using. If you can get on the water early during the week, a small streamer will often draw reaction strikes. Use a two-prong approach, drifting the fly through top of the run, then lift and swing through the bottom half.
On free-flowing rivers, small stones, midge nymphs and attractor patterns (eggs, San Juan Worm, Prince Nymph, etc.) are often productive. Just remember, afternoon fishing will be best after the waters warm and fish the deeper runs. Fish are still primarily in a winter pattern.
Antero Reservoir is getting a fair amount of traffic with the liberalized limit and the upcoming draining. Anglers have through the end of the month before the reservoir is closed. Right now, it still has a solid ice coat, but look for the edges to start softening. Very few are having much success. Those working small jigs, such as tubes (try white or pink) are managing a few. If one spot doesn't produce, move to areas with fewer holes.
If Antero doesn't produce, try nearby Elevenmile Reservoir which has been producing fairly well. Most are smaller fish, but a few are reporting fish to 24 inches. A mix of lures/jigs have been working. The only common denominator has been fishing fairly shallow waters, less than 20 feet, and moving as needed (hard to do with 20 inches or more).
Lake trout hunters should consider either Green Mountain or Granby. Of the two, Green Mountain has been producing the best. Anglers working 20-80 feet of water near structure (rocky shore, steep banks, ledges, etc.) with smallish jigs, 1-3 inches are doing well. It's a good idea to tip with either sucker or a worm.
Dave Coulson is the Colorado state editor for www.fishexplorer.com. He contributes a weekly fishing report to the Explore Summit Weekender.