Big Thompson River

Big Thompson River

Difficulty Beginner/Intermediate
Ideal Days To Fish 9/24, 9/26 & 9/27

Weekly Report

Report DateSept. 22, 2022

Since last week, Big Thompson flows have been all over the place, briefly hitting a high of 160 cfs late last week then quickly decreasing in a stair step fashion. Sitting at 52 cfs, Big Thompson flows are low but anglers willing to cover a lot of water and make adjustments throughout the day will still put trout in the net. As the water starts to warm up, surface activity is strong with trout feeding on midges, mayflies and terrestrials. Small midge patterns such as Griffiths Gnats, Midge Clusters and Parachute Adams will produce the best results during the morning. In the afternoon, Parachute Adams, Sparkle Duns, Amy’s Ants, PMXs and Hippy Stompers are the way to go. Trailing a Black Beauty, RS2, Chocolate Foam Back Emerger or Blue Poison Tung is effective when fishing midge and mayfly patterns. With hoppers, you can trail multiple nymphs and utilize tungsten bead nymphs or split shot to get your flies down into deeper water columns. Hare’s Ears, red Copper Johns, Frenchies, Rainbow Warriors, Perdigons and Prince Nymphs are good examples. Pronounced pools, runs, pockets, outer seams, shallow riffles and transitions are holding trout right now. Once you’ve covered every inch of a particular run, pool, pocket, seam or riffle and made multiple depth changes, move on and sample new water.

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.