Arizona Game and Fish 

Lees Ferry long term monitoring

David Rogowski

Jan Boyer, Pilar Wolters 

Arizona Game and Fish Department Photo – Lees Ferry Anglers

Draft-please do not cite
Lees Ferry Reach monitoring 2017

Draft-please do not cite

Arizona 

Paria River 

Area of detail 

Glen Canyon Dam 

Colorado River 

Lees Ferry 

• 

• 

J 

.,. -5 .. 

•, 

~. 

•••• •••••• 

• I -10 

e v ~- • 

. • 

/ Lake Powell 2 

c? 

Legend 

201 7 sample sites 

• FALL 

ai SPRING 

• SUMMER * River Mile 

1 0 1 2 miles 
Purpose

AGFD manages the Rainbow Trout fishery based 

on a variety of guidance documents 

• NPS 2013

• Rogers 2015 (AGFD Management Plan)

• LTEMP ROD: US DOI 2016a, 2016b 

• (5) maintenance of a high quality sport fishery in 

the Lees Ferry reach

leesferryflyfishing.blogspot.com
AGFD Fisheries Management Plan for Colorado 

River-Lees Ferry 

• Maintain a healthy population of Rainbow Trout at Lees Ferry to 

support recreational fishing

– Rainbow Trout ≤ 6 inches compose 20-50% of the Lees Ferry population as 

determined by fall electrofishing

– Rainbow Trout electrofishing CPUE exceeds 1 fish per minute

• Provide a quality trout fishing experience with catch frequency 

commensurate with the Blue Ribbon status of the fishery

– Angler catch rate ≥ 1 Rainbow Trout per hour

• Grow quality sized trout that are available to the angler, consistent 

with the Blue Ribbon status of the fishery

– 10 Rainbow Trout ≥ 14 inches caught by the angler in a 10-hour day, at least 

one ≥ 20 inches

– Maintain trout condition factor ≥ 1 during the summer months

Draft-please do not cite
Lees Ferry – Long term monitoring

• Electrofishing

• Creel (angler) surveys

• Game camera

Photo by Lees Ferry Anglers, 

6 November 2017
Date n RBT BNT Carp FMS GSF Walleye

14-17 

March 41 551 37 2 3 0 0

17-21 July 41 1178 15 0 0 1 1

12-15 Sept. 40 2458 16 5 17 1 0

Total 4187 68 7 20 2 1

% catch 97.7 1.59 0.163 0.47 0.047 0.023

2017 Electrofishing summary
Year

1992 1995 1998 2001 2004 2007 2010 2013 2016

Rainbow Trout 

CPUE electrofishing (fish/minute)

0

2

4

6

8

10

Rainbow Trout electrofishing 

CPUE

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Year

2000 2002 2004 2006 2008 2010 2012 2014 2016 2018

Fall juvenile Rainbow Trout CPUE (fish/min)

0

2

4

6

8

10

12

14

16

Rainbow Trout CPUE (fish/minute)

Fall juvenile (<152 mm, < 6 in)

Draft-please do not cite
Fall 

Rainbow 

Trout

length 

frequency 

histograms 

by year

n= 42

200

n= 38

201

n= 10

201

n= 27

200

n= 16

201

n= 10

201

n= 1

200

n= 1

201

n= 2

201

n= 14

201

n= 18

201

010020030040050001002003004005000100200300400500

0100200300400500

0

200

400

600

0

200

400

600

0

200

400

600

Total Length (mm)

Number of Fish
<152 mm TL

1990 1995 2000 2005 2010 2015

CPUE (fish/min)

0

3

6

152-305 mm TL

1990 1995 2000 2005 2010 2015

0

3

6

>305-405 mm TL

Year

1990 1995 2000 2005 2010 2015

CPUE (fish/min)

0

1

2

>405 mm TL

Year

1990 1995 2000 2005 2010 2015

0

1

A

C D

B

Rainbow 

Trout

by size 

category

6-12 

inches

12-16 

inches

> 16 inches

< 6 inches

Draft-please do not cite
AGFD long-term monitoring electrofishing

0e+00

1e+05

2e+05

3e+05

4e+05

5e+0519910208 19910504 19911104

19920223199205191992082419921111199303091993050319930929199404051994041919940725199412051995051219951204199603231996040519960827199611181997041919970830199712051998041719980808199811161999050519991001199912172000032720000627200009262000120420010404200106222001100120020314200203272002062720021015200304282003080420031103200404262004071220041101200412062005040420050628200511282006040420060626200610102007042420070724200710302008022820080318200807142008102820090421200907142009110320100427201006302010072120101026201104122011072520111018201204092012071720121015201303252013071620131021201403182014071420140930201503172015070620151005201603152016071820160913201703142017071720170912

TRIP_ID

TL_calc

len_cat

big >16

adult 12-16

sub_a 6-12

juve <6

Proportional abundance

Date

Oct 2011

Sept 2014 Last stocking

4 June 1998

Oct 2008

Oct 2004

Draft-please do not cite
AGFD long-term monitoring 

electrofishing 2008-2017

0e+00

1e+05

2e+05

3e+05

4e+05

5e+05

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 201

Year

Proportional Abundance

big >16

adult 12-16

sub_a 6-12

juve <6
Catch per unit effort (fish/minute)

0.80 0.85 0.90 0.95 1.00 1.05 1.10 1.15

Log(relative fish condition (Kn))

-1.0

-0.8

-0.6

-0.4

-0.2

0.0

0.2

0.4

0.6

Subadult 

Adult 

Rainbow trout abundance and relative 

condition (Kn)

Draft-please do not cite
Rainbow Trout 

relative 

condition (Kn) 

by size class

Photo by D. Gauthier, Lees Ferry 

Anglers, 5 June 2017

152 - 305 mm

Rainbow trout fish condition (Kn)

0.8

1.0

1.2

1.4

306 - 405 mm

0.8

1.0

1.2

1.4

 > 405 mm

Date

1/1/1990 1/1/1992 1/1/1994 1/1/1996 

1/1/1998 1/1/2000 1/1/2002 1/1/2004 

1/1/2006 1/1/2008 

1/1/2010 

1/1/2012 

1/1/2014 

1/1/2016 

1/1/2018 

0.4

0.6

0.8

1.0

1.2

1.4

Fall 2015

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Year

1975 1980 1985 1990 1995 2000 2005 2010 2015

Angler CPUE (fish/hour)

0.00

0.25

0.50

0.75

1.00

1.25

1.50

1.75

2.00

2.25

2.50

Boat angler CPUE 

Walk-in angler CPUE 

Angler CPUE (fish/hour)

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Year

2011 2012 2013 2014 2015 2016 2017

Average yearly angler satisfaction

0

1

2

3

4

5

6

boat 

walk-in 

Angler Satisfaction rating (1-5)

Photo: Lees Ferry Anglers

Draft-please do not cite
Year

1980 1984 1988 1992 1996 2000 2004 2008 2012 2016 2020

Yearly relative angler use

0

2500

5000

7500

10000

12500

15000

17500

20000

boat anglers 

walk-in anglers

Relative angler use

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Rainbow Trout harvested

(n = number of fish)

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Brown Trout

• Concern?

https://www.pinterest.com/pin/5426838238244

Kevin Campbell 4 Sept 2015 30236/ Lees Ferry Anglers

Draft-please do not cite
Year

2000 2002 2004 2006 2008 2010 2012 2014 2016 2018

Average yearly CPUE (fish/minute)

0.00

0.02

0.04

0.06

0.08

0.10

Brown Trout average electrofishing CPUE 

(fish/minute)
Brown 

Trout 

length 

frequency 

histograms

1996

n= 1

2003

n= 4

2007

n= 3

2012

n= 5

2016

n= 7

1999

n= 1

2004

n= 3

2008

n= 4

2013

n= 1

2017

n= 7

2000

n= 1

2005

n= 5

2010

n= 1

2014

n= 2

2001

n= 2

2006

n= 2

201

n= 5

2015

n= 5

0 1002003004005006007000 100200300400500600700

01002003004005006007000 100200300400500600700

0

5

10

15

20

0

5

10

15

20

0

5

10

15

20

0

5

10

15

20

0

5

10

15

20

Total Length (mm)

Number of Fish
Brown Trout fall length frequency histograms

2013

n= 4

2016

n= 44

2014

n= 2

2017

n= 16

2015

n= 27

01002003004005000100200300400500

0100200300400500

0

5

10

15

20

0

5

10

15

20

Total Length (mm)

Number of Fish
Total length of Brown Trout by 

river mile 2017

0

100

200

300

400

500

600

-15.5 -13.5 -11.5 -9.5 -7.5 -5.5 -3.5 -1.5 0.5

Total Length

River Mile

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Brown Trout captured by 

anglers

Anglers 

interviewed BNT captured BNT

Year boat walk-in boat walk-in harvested

2011 1075 358 0 0 0

2012 676 239 0 1 0

2013 883 262 11 0 0

2014 1275 375 9 1 2

2015 1545 433 22 1 4

2016 1056 164 6 0 1

2017 940 269 21 3 8
Rare-nonnatives 2017

Species Number Location Program

Smallmouth

Bass 1 -15.73 L Non-native hunt

Walleye 1 -12.2 R Non-native hunt

Brown Trout 2 -15.07R, -10.85L Non-native hunt

Common Carp 32 -12 Slough Non-native hunt

Brown Trout 68 Reach wide Monitoring

Bluegill Sunfish 1 -12.81 L Monitoring

Green Sunfish 2 -5.19 R, -12.35L Monitoring

Draft-please do not cite
Year BKT BNT CRP BGS CCF GSF RSS SMB STB WAL

1992 9 6 2

1993 1 1 1

1994 1 6

1995 1 2 1

1996 1 9 1 1

1997 2 1

1998 1

1999 1

2000 1 3

2001 4 5 1

2002 7

2003 4 19 1

2004 4 15

2005 5 5 1

2006 2 8 1 1

2007 3 4 2

2008 7 15 1 2

2009 5 6 1

2010 3 216 1 3 1 2

2011 8 70 1 7

2012 7 52 4

2013 18 78 1 2 3

2014 23 82 6

2015 53 210 3553 8

2016 70 44 1 5

2017 70 39 1 2 1 1

AGFD

monitoring

non-natives

excluding RBT

Draft-please do not cite
Lees Ferry Summary

• Electrofishing CPUE > 1 fish/minute

• Angling CPUE < 1 fish/minute

• Angler use lower than past, but stable

• Brown Trout (1.59%)– probably not a problem

• Outlook for future better Draft-please do not cite
Acknowledgements

AGFD: Pilar Wolters, Kristy Manuell, Daniel Pasminski

Humphrey Summit & Saint Judes Ltd. - boatmen

All of the volunteers 

Past & present agency personnel

Steve Harding

Lees Ferry Anglers

Draft-please do not cite