The Rio Grande River in southwestern Colorado is absolutely on fire this October! Flows have settled around 300-350 cfs, and the water is cool and clear, with temperatures in the low 50s. This means that brown trout are starting to turn aggressive as they get ready for the spawn, making streamers your new best friend. You’ll also find that trout are actively feeding on midges and Blue-Winged Olives, making nymphing and dry-dropper setups productive throughout the day. With the river surrounded by fall colors and fewer anglers on the water, it’s prime time to chase after big fish in this wild and scenic river.
The Rio Grande in November is a cold, clear, and quiet retreat, ideal for anglers looking to experience the beauty of the San Luis Valley. With flows around 100-150 CFS, the river provides easy wading and great visibility, although trout here can be selective in the colder conditions. Midges and Blue Wing Olives are the main hatches, with trout feeding in deeper pools and slower runs. The Rio Grande is known for its wild browns and rainbows, making it an enticing challenge for those who enjoy technical fishing with smaller flies.
Late morning to mid-afternoon offers the best fishing, especially on sunnier days. Nymphing will be your most productive technique, but a well-presented Blue Wing Olive dry fly can still turn some heads during midday hatches. Streamer fishing can bring out larger fish in the early morning or late afternoon, particularly near undercut banks and deep runs.
| Month | Primary Hatches | Effective Patterns |
|---|---|---|
| March | Midges, Baetis (BWO) | Zebra Midges (#20-24), Blue Wing Olive (#18-22) |
| April | Midges, Baetis, Caddis | Black Beauty (#18-22), Elk Hair Caddis (#16-18) |
| May | Baetis, Caddis, Stoneflies | Blue Wing Olive (#18-20), Pat’s Rubber Legs (#10-12) |
| June | Caddis, PMDs | Elk Hair Caddis (#16), PMD Comparadun (#16-18) |
| July | Caddis, Yellow Sallies | Yellow Sally (#14-16), PMD Emerger (#18-20) |
| August | Tricos, Caddis, Terrestrials | Trico Spinner (#22-24), Parachute Hopper (#10-12) |
| September | BWOs, Midges, Caddis | BWO Parachute (#18-22), Black Ant (#18-20) |
| October | BWOs, Midges | Blue Wing Olive (#18-22), Zebra Midge (#20-24) |
| November | BWOs, Midges | BWO Emerger (#18-22), Black Beauty (#20-24) |
| December - February | Midges | Griffith’s Gnat (#20-24), WD-40 (#18-22) |
Seasonal Tip
With cold temperatures, trout activity peaks around midday. Approach quietly and focus on calmer water for your best chance at a strike.
Dry Fly
BWOs in late morning provide dry fly opportunities. Cast to risers in slower pools, using light tippet to prevent spooking fish in clear water.
Nymphing
A small Zebra Midge paired with a Baetis nymph works well, especially in riffles and deeper pools where trout hold and feed in winter conditions.
Streamer Fishing
For larger fish, work an Olive Woolly Bugger through deeper pockets and around structure. Slow retrieves near undercut banks are often rewarded with aggressive strikes.
The Rio Grande includes both public and private access points, so always check for public access or stick to designated areas. Catch-and-release practices are recommended, as well as the use of barbless hooks to protect the trout population. Ensure you have a valid Colorado fishing license, and always respect private land boundaries when fishing near the San Luis Valley.