Yellowtail Afterbay Reservoir fishing

Yellowtail Afterbay Reservoir fishing is stocked with Rainbow Trout, Walleye, and Cutthroat Trout on a reservoir. Also recorded: Brown Trout, Smallmouth Bass, Yellow Perch, Crappie, Burbot, Channel Catfish, and 1 more. It is stocked about 1.4 times a year since 2011, most often in April and May. Species guides list dawn and dusk for Rainbow Trout, Smallmouth Bass, and Common Carp, dawn, dusk, and night for Walleye and Crappie, and dawn, day, and dusk for Brown Trout and Yellow Perch.

AI-generated illustration, not a photo of this lake
Last stocked
May 6, 2026
· Rainbow Trout
Plants on record
22
Since 2011
Species stocked
3 (+7 also recorded)
Average size
4.4 in
Elevation
3,195 ft

Fish at Yellowtail Afterbay Reservoir

3 stocked · 7 confirmed present

Around the dates Yellowtail Afterbay Reservoir is stocked, Open-Meteo's 2016-2025 archive puts mean air temperature at 55.4°F in May, 44.2°F in April, 73.1°F in August, 75.1°F in July. That is air temperature at these coordinates, not water temperature. Open-Meteo

Rainbow Trout Stocked · 19 plants · last May 6, 2026 Best: dawn, dusk

Last stocked May 6, 2026 · avg 4.7 in · 19 plants

Best: dawn, dusk

Rainbow Trout species guide
Walleye Stocked · 2 plants · last July 18, 2012 Best: dawn, dusk, night

Last stocked July 18, 2012 · avg 2.4 in · 2 plants

Best: dawn, dusk, night

Walleye species guide

How Yellowtail Afterbay Reservoir is stocked

Source: Montana Fish, Wildlife & Parks.

No plants recorded in 2022.

Fish stocked in 2011

23,021

Fish stocked in 2012

127,484

Fish stocked in 2013

31,025

Fish stocked in 2014

30,566

Fish stocked in 2015

41,962

Fish stocked in 2016

26,432

Fish stocked in 2017

24,209

Fish stocked in 2018

47,164

Fish stocked in 2019

20,880

Fish stocked in 2020

24,746

Fish stocked in 2021

14,960

Fish stocked in 2023

12,970

Fish stocked in 2024

10,173

Fish stocked in 2025

14,960

Fish stocked in 2026

6,239

Stocking history

Source: Montana Fish, Wildlife & Parks.
Date Species Quantity Avg. length Source
May 6, 2026Rainbow Trout6,2395.1 inreport
April 2, 2025Rainbow Trout6,6494.5 inreport
April 1, 2025Rainbow Trout8,3114.3 inreport
May 7, 2024Rainbow Trout10,1734.65 inreport
May 10, 2023Rainbow Trout12,9704.65 inreport
May 10, 2021Rainbow Trout14,9604.41 inreport
August 12, 2020Cutthroat Trout6,5802.95 inreport
May 13, 2020Rainbow Trout18,1664.2 inreport
May 15, 2019Rainbow Trout20,8804.57 inreport
May 7, 2018Rainbow Trout23,5824.12 inreport
May 7, 2018Rainbow Trout23,5824.12 inreport
October 4, 2017Rainbow Trout9525.4 inreport
August 8, 2017Rainbow Trout10,6117.26 inreport
August 7, 2017Rainbow Trout12,6466.92 inreport
April 29, 2016Rainbow Trout26,4324.05 inreport
October 6, 2015Rainbow Trout10,4105.06 inreport
May 11, 2015Rainbow Trout31,5524.18 inreport
May 27, 2014Rainbow Trout30,5664.41 inreport
May 1, 2013Rainbow Trout31,0253.89 inreport
July 18, 2012Walleye36,6922.37 inreport
July 17, 2012Walleye90,7922.37 inreport
May 2, 2011Rainbow Trout23,0214.15 inreport

Access and facts

Water type
reservoir
Nearest town
Fort Smith
Facilities
camping, restrooms

Afterbay Lake runs 2.2 miles from Yellowtail Dam to Afterbay Dam near Fort Smith and can rise or fall 15 feet in a day. It is fished from shore and by boat, with lake access near Government Camp and Afterbay Campground on the bay. The Afterbay ramp below the dam launches onto the Bighorn River.

Drafted by AI from the cited sources and checked before publishing.

View larger map · Open in Google Maps · Directions

Advisories, closures, regulations and water conditions change. Check the Montana Fish, Wildlife & Parks before you go.

Nearest lakes

Bighorn Lake 0.7 mi last stocked July 7, 2026 Sage Creek 35.2 mi last stocked September 25, 2014 Arapooish Pond 36.3 mi last stocked September 12, 2023 Lake Josephine 40.8 mi last stocked September 4, 2025 Shiloh Conservation Pond 1 44.3 mi last stocked August 11, 2026

Public land at Yellowtail Afterbay Reservoir

Yellowtail Afterbay Reservoir is 0.5 miles outside the edge of Bighorn Canyon National Recreation Area.

Boundaries from Public Lands DB, part of the same network.

Common questions

What fish are at Yellowtail Afterbay Reservoir?

Fishing Yellowtail Afterbay Reservoir usually means Rainbow Trout: Rainbow Trout accounts for 19 of 22 plants on record, ahead of Walleye and one more. Rainbow Trout was last stocked May 6, 2026, averaging 4.7 in. Walleye was last stocked July 18, 2012, averaging 2.4 in. Cutthroat Trout was last stocked August 12, 2020, averaging 3 in. Brown Trout, Smallmouth Bass, Yellow Perch, and Crappie, plus 3 more are recorded here outside the stocking reports.

When is Yellowtail Afterbay Reservoir stocked?

Last stocked May 6, 2026. It is stocked about 1.4 times a year since 2011, most often in April and May. No plants recorded in 2022.

How big are the fish stocked at Yellowtail Afterbay Reservoir?

Stocked fish average 4.4 in. Rainbow Trout average 4.7 in. Walleye average 2.4 in. Cutthroat Trout average 3 in.

How do you get on Yellowtail Afterbay Reservoir?

The nearest town is Fort Smith. Facilities include camping and restrooms. Afterbay Lake runs 2.2 miles from Yellowtail Dam to Afterbay Dam near Fort Smith and can rise or fall 15 feet in a day. It is fished from shore and by boat, with lake access near Government Camp and Afterbay Campground on the bay. The Afterbay ramp below the dam launches onto the Bighorn River.

Which lakes near Yellowtail Afterbay Reservoir were stocked more recently?

Bighorn Lake (0.7 mi) and Shiloh Conservation Pond 1 (44.3 mi) were stocked more recently. Bighorn Lake is also stocked with Walleye and Rainbow Trout and Shiloh Conservation Pond 1 is also stocked with Rainbow Trout and Cutthroat Trout.

Sources (6) +