Waterton Canyon: Below Strontia Springs

Waterton Canyon — Fishing Report for April 27, 2026

Quick Stats

Flow: 25 CFS | Trend: Rising | Fishability: Fair | Weather: Chance rain and thunderstorms, high 55°F

The Bite

Overcast skies and a good chance of afternoon showers make today one of the better BWO setups of the spring — even if the flows aren't cooperating the way they should be. At 25 CFS, the South Platte through Waterton Canyon is running well below the ideal 80–200 CFS window, and significantly below the seasonal norm for late April. With the basin carrying just a fraction of its normal snowpack this year, don't expect a dramatic spring surge — what you're seeing now is likely close to what April will finish with.

The low, clear water is the defining challenge today. Fish will be spooky and spread thin across the streambed, holding in the deeper slots and undercut banks rather than spreading into the riffles. Long leaders, fine tippet, and careful wading are non-negotiable. The upside: low, clear conditions make it easier to spot rising fish, and the overcast forecast should trigger BWO activity between noon and 4 PM. If the cloud cover holds and rain stays light, expect pods of risers in the slower tailouts and along the softer inside seams.

Mornings are a nymphing game. Scuds and aquatic worms remain reliable year-round producers in this tailwater, and with flows this low, a single well-placed nymph will outfish a heavy two-fly rig that drags bottom. Keep your approach stealthy — these fish have seen pressure and the gin-clear water gives them every advantage.

What to Fish

• RS-2 #20-22 — The afternoon dry fly anchor. Fish it in the film or just below as an emerger during the BWO window.
• Sparkle Dun BWO #20-22 — Excellent when fish are keying on emerging duns; trail it 12–16" behind a Parachute BWO as a dry-dry combo if surface activity is strong.
• Scud (orange/pink) #16 — Morning nymph workhorse. Natural presentation along the bottom near any visible weed growth.
• San Juan Worm (red) #14 — With rain in the forecast and a slight rise in flows, this is worth having on point in the morning.
• Jujubaetis #20-22 — Transition fly as BWO activity builds late morning; fish it as a single nymph on 6X.
• Pheasant Tail #18-20 — Reliable backup nymph when fish aren't committing to the scud.

Tactics & Rigging

For the morning, rig a single weighted nymph — a San Juan Worm or scud on point — under a small indicator or as a tight-line setup. With flows this low, a two-fly rig risks hanging up constantly and spooking fish in the shallow water. Keep it simple: 9-foot leader to 5X, then 18" of 6X fluorocarbon to your fly. Fish the deeper slots and any water with visible current seams.

As cloud cover builds toward midday, watch for the first risers. When you see them, switch to a 12-foot leader tapered to 6X or 7X and tie on a single RS-2 or Sparkle Dun. Pick one fish, get into position without wading through the pod, and let the fly ride the current naturally through the fish's feeding lane. In water this clear, a drag-free presentation matters more than pattern selection — a perfect drift on a mediocre fly beats a sloppy drift on the right one every time.

Access & Logistics

Waterton Canyon is hike- or bike-in only — no vehicle access beyond the trailhead gate. The paved trail makes for easy going, but plan on at least a mile of walking before you reach quality water. Check CPW alerts before heading out: bighorn sheep lambing season can trigger temporary trail closures in the canyon. Before fishing, clean, drain, and dry all wading gear — New Zealand mudsnails have been documented in the South Platte drainage and every angler plays a role in keeping them contained.

Verify current regulations with CPW before fishing — the catch-and-release and size restrictions in this section can change.

Stop by Trouts Fly Fishing or Confluence Anglers for flies, local intel, and to support the shops that keep these fisheries healthy.

Looking Ahead

Rain continues through Tuesday with a mix of showers and thunderstorms — watch flows closely, as any significant runoff could push clarity down temporarily. By Wednesday, a slight warm-up toward 60°F could bring the first reliable caddis scouts of the season alongside the BWOs.