Big Thompson River

Big Thompson River

Difficulty Beginner/Intermediate
Ideal Days To Fish 4/9, 4/10 & 4/12

Weekly Report

Report DateApril 8, 2021
Big Thompson flows are on the rise below Lake Estes. Flows are currently sitting at 65 cfs and with most of the ice cleared up, the Big T is fishing well! Elevated flows have allowed trout to spread out from their winter lies and feed in a variety of sections. Slow pools and runs continue to be productive during the morning hours but once the water warms up in the afternoon and bug activity picks up, focus on slow riffles, transitions, pockets, seams and tailouts. Nymph rigs are a consistent and productive approach but don’t rule out dry fly and dry dropper setups. Trout are looking up at the surface to feed, so stock up on Mole Flies, Griffiths Gnats and Parachute Adams. If trout are sipping below the surface, trail an RS2 or Chocolate Foam Back Emerger 8 – 12 inches behind your dry. When nymphing, lead with a large or flashy attractor and trail a midge pupa or baetis emerger. Mini Leeches, eggs, Rainbow Warriors, Pheasant Tails and Buckskins are productive lead options. Mercury Black Beauties, red/purple Zebra Midges, Chocolate Foam Backs, RS2s and Blue Poison Tungs will get the job done in the trailer position.

Recommended Flies

River Flow

Flow Region

Detailed River Info


The Big Thompson, commonly referred to as the Big T, is a beautiful river that originates high in Rocky Mountain National Park. This small-medium sized river flows through Rocky Mountain National Park and the town of Estes Park before feeding into Lake Estes. Below Lake Estes, the river continues along Highway 34 through Drake, eventually making its way to the town of Loveland. The Big T flows through various types of terrain, offering anglers a variety of scenic and fishing opportunities. The stretch of river that flows through Rocky Mountain National Park is in an open meadow setting and contains brown trout, rainbow trout, brook trout and if you’re lucky, greenback cutthroat. Below Lake Estes, anglers will find themselves in a canyon setting dominated by pocket water with a select number of deep pools and runs. Brown and rainbow trout in the 10 – 12” range can be found in this stretch.


The Big Thompson is a diverse river that is friendly to anglers of all skill sets. The stretch that flows through Moraine Park in Rocky Mountain National Park is highly sought after during the summer months. During the summer, this stretch tends to see a lot of foot traffic, so stealthy fishing is required to not spook the trout. Fishing dry and dry dropper setups is the preferred method in Moraine Park. Below Lake Estes, pocket water is prevalent, which may test your ability to fish tight pockets. Nymphing is a productive method year-round, while dry and dry dropper setups are productive during the summer and fall. Overall, the ideal time to fish the Big Thompson is during the summer and fall months. However, if you’re looking to fish during the winter, the section directly below the Lake Estes/Olympus Dam is classified as a tailwater and usually remains ice-free.

River Access

The Big Thompson has many access points with varying levels of difficulty. In order to fish Moraine Park, anglers will need to purchase a $25 National Parks day pass. Moraine Park is located just under 3 miles from the Beaver Meadows Entrance Station on the south side of Estes Park. Below Lake Estes, anglers can access the tailwater section via a public park on Mall Rd. Downstream of the tailwater, there are a number of pull offs along Highway 34 that anglers can use to access the river.  Be conscious of private property when fishing along Highway 34. In general, the bank that borders the road is public and the property along the far bank tends to be private.