Minnesota Fishing Guide

Big Stony

Hubbard County, Minnesota — DOW #29014300

217 Surveys
343.38
Acres
24 ft
Max Depth
10 ft
Mean Depth
11
Fish Species
6
Local Guides

DNR Fish Surveys

Catch-per-unit-effort (CPUE) data from Minnesota DNR fish population assessments on Big Stony. Green = above normal range. Red = below normal.

Northern Pike

Date Gear CPUE Normal Range Avg Weight Total Catch
1975-08-01 Standard gill nets 6.5 (normal) 2.3 – 9.2 3.35 lb 13
1975-08-01 Standard trap nets 0.4 — 3.20 lb 4
1992-07-22 Standard gill nets 7.3 (normal) 2.3 – 9.2 2.33 lb 44
1992-07-22 Standard trap nets 0.9 — 1.66 lb 9
1982-06-23 Standard gill nets 13.0 (above normal) 2.3 – 9.2 1.40 lb 52
1982-06-23 Standard trap nets 0.2 — 0.50 lb 2
2007-07-30 Standard gill nets 1.8 (below normal) 2.3 – 9.2 3.16 lb 16
2007-07-30 Standard trap nets 1.1 — 3.68 lb 10
2002-07-08 Standard gill nets 4.9 (normal) 2.3 – 9.2 1.96 lb 44
2002-07-08 Standard trap nets 1.6 — 2.86 lb 14
2022-08-01 Standard gill nets 2.1 (below normal) 2.3 – 9.2 1.82 lb 19
2022-08-01 Standard trap nets 0.6 — 2.33 lb 5
1987-07-08 Standard gill nets 8.8 (normal) 2.3 – 9.2 1.34 lb 35
1987-07-08 Standard trap nets 1.1 — 1.25 lb 11
1997-07-14 Standard gill nets 5.8 (normal) 2.3 – 9.2 2.00 lb 35
1997-07-14 Standard trap nets 1.0 — 1.32 lb 9
2012-07-30 Standard gill nets 5.1 (normal) 2.3 – 9.2 1.82 lb 46
2012-07-30 Standard trap nets 0.4 — 1.88 lb 4

Black Crappie

Date Gear CPUE Normal Range Avg Weight Total Catch
1975-08-01 Standard gill nets 1.5 (normal) 0.8 – 8.4 0.33 lb 3
1975-08-01 Standard trap nets 4.3 (normal) 0.9 – 8.0 0.30 lb 43
1992-07-22 Standard gill nets 0.3 (below normal) 0.8 – 8.4 0.25 lb 2
1992-07-22 Standard trap nets 1.1 (normal) 0.9 – 8.0 0.47 lb 11
1982-06-23 Standard gill nets 0.8 (below normal) 0.8 – 8.4 0.28 lb 3
2007-07-30 Standard gill nets 7.2 (normal) 0.8 – 8.4 0.19 lb 65
2007-07-30 Standard trap nets 5.8 (normal) 0.9 – 8.0 0.25 lb 52
2002-07-08 Standard gill nets 0.9 (normal) 0.8 – 8.4 0.30 lb 8
2002-07-08 Standard trap nets 1.7 (normal) 0.9 – 8.0 0.27 lb 15
2022-08-01 Standard gill nets 2.1 (normal) 0.8 – 8.4 0.28 lb 19
2022-08-01 Standard trap nets 8.3 (above normal) 0.9 – 8.0 0.35 lb 66
1987-07-08 Standard gill nets 0.5 (below normal) 0.8 – 8.4 0.55 lb 2
1987-07-08 Standard trap nets 0.6 (below normal) 0.9 – 8.0 0.27 lb 6
1997-07-14 Standard gill nets 0.2 (below normal) 0.8 – 8.4 0.42 lb 1
1997-07-14 Standard trap nets 0.7 (below normal) 0.9 – 8.0 0.43 lb 6
2012-07-30 Standard gill nets 2.6 (normal) 0.8 – 8.4 0.44 lb 23
2012-07-30 Standard trap nets 1.8 (normal) 0.9 – 8.0 0.39 lb 16

Bluegill

Date Gear CPUE Normal Range Avg Weight Total Catch
1975-08-01 Standard trap nets 77.2 (above normal) 5.9 – 43.3 0.15 lb 772
1992-07-22 Standard gill nets 7.0 — 0.24 lb 42
1992-07-22 Standard trap nets 51.6 (above normal) 5.9 – 43.3 0.17 lb 516
2017-08-02 Backpack electrofishing 10.3 — — 12
2017-08-02 15-ft beach seine 4.8 — — 19
2017-08-02 50-ft beach seine 31.7 — — 190
1982-06-23 Standard trap nets 101.3 (above normal) 5.9 – 43.3 0.17 lb 1013
1982-06-23 Standard gill nets 2.8 — 0.16 lb 11
2007-07-30 Standard gill nets 9.6 — 0.14 lb 86
2007-07-30 Standard trap nets 62.0 (above normal) 5.9 – 43.3 0.12 lb 558
2002-07-08 Standard gill nets 4.1 — 0.06 lb 37
2002-07-08 Standard trap nets 71.7 (above normal) 5.9 – 43.3 0.04 lb 645
2022-08-01 Standard gill nets 3.8 — 0.20 lb 34
2022-08-01 Standard trap nets 18.3 (normal) 5.9 – 43.3 0.20 lb 146
1987-07-08 Standard gill nets 4.0 — 0.07 lb 16
1987-07-08 Standard trap nets 42.3 (normal) 5.9 – 43.3 0.11 lb 423
1997-07-14 Standard gill nets 2.0 — 0.08 lb 12
1997-07-14 Standard trap nets 26.7 (normal) 5.9 – 43.3 0.18 lb 240
2012-07-30 Standard gill nets 7.6 — 0.31 lb 68
2012-07-30 Backpack electrofishing 77.0 — — 44
2012-07-30 Standard trap nets 28.1 (normal) 5.9 – 43.3 0.23 lb 253
2012-07-30 50-ft beach seine 2.0 — — 2
2012-07-30 15-ft beach seine 47.8 — — 239

Yellow Perch

Date Gear CPUE Normal Range Avg Weight Total Catch
1975-08-01 Standard trap nets 0.8 (normal) 0.5 – 3.7 0.16 lb 8
1975-08-01 Standard gill nets 13.0 (normal) 3.7 – 28.4 0.29 lb 26
1992-07-22 Standard trap nets 0.8 (normal) 0.5 – 3.7 0.20 lb 8
1992-07-22 Standard gill nets 21.3 (normal) 3.7 – 28.4 0.23 lb 128
2017-08-02 15-ft beach seine 0.5 — — 2
2017-08-02 50-ft beach seine 9.3 — — 56
1982-06-23 Standard gill nets 17.5 (normal) 3.7 – 28.4 0.21 lb 70
2007-07-30 Standard trap nets 0.3 (below normal) 0.5 – 3.7 0.18 lb 3
2007-07-30 Standard gill nets 1.1 (below normal) 3.7 – 28.4 0.19 lb 10
2002-07-08 Standard trap nets 0.4 (below normal) 0.5 – 3.7 0.21 lb 4
2002-07-08 Standard gill nets 1.0 (below normal) 3.7 – 28.4 0.16 lb 9
2022-08-01 Standard gill nets 2.7 (below normal) 3.7 – 28.4 0.19 lb 24
1987-07-08 Standard trap nets 1.0 (normal) 0.5 – 3.7 0.19 lb 10
1987-07-08 Standard gill nets 5.8 (normal) 3.7 – 28.4 0.18 lb 23
1997-07-14 Standard trap nets 0.3 (below normal) 0.5 – 3.7 0.20 lb 3
1997-07-14 Standard gill nets 9.5 (normal) 3.7 – 28.4 0.16 lb 57
2012-07-30 Standard gill nets 2.8 (below normal) 3.7 – 28.4 0.19 lb 25
2012-07-30 Backpack electrofishing 1.8 — — 1

Largemouth Bass

Date Gear CPUE Normal Range Avg Weight Total Catch
1975-08-01 Standard trap nets 0.6 (normal) 0.3 – 1.0 0.53 lb 6
1975-08-01 Standard gill nets 1.5 (normal) 0.3 – 1.5 1.08 lb 3
1992-07-22 Standard gill nets 2.7 (above normal) 0.3 – 1.5 0.59 lb 16
1992-07-22 Standard trap nets 2.3 (above normal) 0.3 – 1.0 0.31 lb 23
2017-08-02 Backpack electrofishing 29.3 — — 34
2017-08-02 15-ft beach seine 29.8 — — 119
2017-08-02 50-ft beach seine 25.2 — — 151
1982-06-23 Standard trap nets 0.7 (normal) 0.3 – 1.0 0.16 lb 7
1982-06-23 Standard gill nets 0.3 (below normal) 0.3 – 1.5 2.00 lb 1
2007-07-30 Standard gill nets 7.6 (above normal) 0.3 – 1.5 0.83 lb 68
2007-07-30 Standard trap nets 1.1 (above normal) 0.3 – 1.0 0.47 lb 10
2002-07-08 Standard gill nets 2.1 (above normal) 0.3 – 1.5 0.72 lb 19
2002-07-08 Standard trap nets 0.2 (below normal) 0.3 – 1.0 0.14 lb 2
2022-08-01 Standard gill nets 4.2 (above normal) 0.3 – 1.5 0.67 lb 38
2022-08-01 Standard trap nets 0.9 (normal) 0.3 – 1.0 1.21 lb 7
1987-07-08 Standard gill nets 1.5 (normal) 0.3 – 1.5 0.45 lb 6
1987-07-08 Standard trap nets 1.1 (above normal) 0.3 – 1.0 0.54 lb 11
1997-07-14 Standard gill nets 0.3 (normal) 0.3 – 1.5 0.43 lb 2
1997-07-14 Standard trap nets 0.3 (normal) 0.3 – 1.0 1.64 lb 3
2012-07-30 15-ft beach seine 0.4 — — 2
2012-07-30 Standard gill nets 3.4 (above normal) 0.3 – 1.5 0.88 lb 31
2012-07-30 Standard trap nets 0.9 (normal) 0.3 – 1.0 0.22 lb 8

Yellow Bullhead

Date Gear CPUE Normal Range Avg Weight Total Catch
1975-08-01 Standard gill nets 52.5 (above normal) 1.0 – 8.0 0.31 lb 105
1975-08-01 Standard trap nets 4.6 (normal) 2.4 – 9.1 0.30 lb 46
1992-07-22 Standard gill nets 8.0 (normal) 1.0 – 8.0 0.35 lb 48
1992-07-22 Standard trap nets 2.8 (normal) 2.4 – 9.1 0.37 lb 28
2017-08-02 Backpack electrofishing 1.7 — — 2
2017-08-02 15-ft beach seine 0.5 — — 2
1982-06-23 Standard gill nets 26.8 (above normal) 1.0 – 8.0 0.22 lb 107
1982-06-23 Standard trap nets 28.3 (above normal) 2.4 – 9.1 0.27 lb 283
2007-07-30 Standard gill nets 6.6 (normal) 1.0 – 8.0 0.61 lb 59
2007-07-30 Standard trap nets 1.8 (below normal) 2.4 – 9.1 0.69 lb 16
2002-07-08 Standard gill nets 0.1 (below normal) 1.0 – 8.0 0.36 lb 1
2002-07-08 Standard trap nets 0.7 (below normal) 2.4 – 9.1 0.90 lb 6
2022-08-01 Standard gill nets 2.8 (normal) 1.0 – 8.0 0.61 lb 25
2022-08-01 Standard trap nets 0.8 (below normal) 2.4 – 9.1 0.61 lb 6
1987-07-08 Standard gill nets 14.0 (above normal) 1.0 – 8.0 0.18 lb 56
1987-07-08 Standard trap nets 7.5 (normal) 2.4 – 9.1 0.26 lb 75
1997-07-14 Standard gill nets 0.7 (below normal) 1.0 – 8.0 0.25 lb 4
1997-07-14 Standard trap nets 0.6 (below normal) 2.4 – 9.1 0.73 lb 5
2012-07-30 Backpack electrofishing 1.8 — — 1
2012-07-30 Standard trap nets 1.0 (below normal) 2.4 – 9.1 0.68 lb 9
2012-07-30 Standard gill nets 3.2 (normal) 1.0 – 8.0 0.55 lb 29

White Sucker

Date Gear CPUE Normal Range Avg Weight Total Catch
1975-08-01 Standard trap nets 0.3 (normal) 0.3 – 1.3 3.25 lb 3
1992-07-22 Standard gill nets 1.5 (normal) 0.5 – 3.3 2.87 lb 9
1982-06-23 Standard gill nets 1.3 (normal) 0.5 – 3.3 2.45 lb 5
2007-07-30 Standard gill nets 5.3 (above normal) 0.5 – 3.3 2.29 lb 48
2002-07-08 Standard gill nets 9.3 (above normal) 0.5 – 3.3 1.60 lb 84
2002-07-08 Standard trap nets 2.6 (above normal) 0.3 – 1.3 2.21 lb 23
2022-08-01 Standard gill nets 2.7 (normal) 0.5 – 3.3 1.90 lb 24
2022-08-01 Standard trap nets 1.8 (above normal) 0.3 – 1.3 1.96 lb 14
1987-07-08 Standard gill nets 2.0 (normal) 0.5 – 3.3 2.06 lb 8
1997-07-14 Standard gill nets 11.8 (above normal) 0.5 – 3.3 1.93 lb 71
1997-07-14 Standard trap nets 0.2 (below normal) 0.3 – 1.3 3.28 lb 2
2012-07-30 Backpack electrofishing 1.8 — — 1
2012-07-30 Standard trap nets 0.2 (below normal) 0.3 – 1.3 2.93 lb 2
2012-07-30 50-ft beach seine 1.0 — — 1
2012-07-30 Standard gill nets 3.4 (above normal) 0.5 – 3.3 2.86 lb 31

Pumpkinseed

Date Gear CPUE Normal Range Avg Weight Total Catch
1975-08-01 Standard trap nets 8.7 (normal) 1.5 – 9.1 0.16 lb 87
1992-07-22 Standard gill nets 1.5 — 0.27 lb 9
1992-07-22 Standard trap nets 7.0 (normal) 1.5 – 9.1 0.24 lb 70
2017-08-02 50-ft beach seine 0.2 — — 1
1982-06-23 Standard gill nets 2.3 — 0.14 lb 9
1982-06-23 Standard trap nets 22.8 (above normal) 1.5 – 9.1 0.20 lb 228
2007-07-30 Standard gill nets 6.2 — 0.21 lb 56
2007-07-30 Standard trap nets 16.7 (above normal) 1.5 – 9.1 0.19 lb 150
2002-07-08 Standard gill nets 4.8 — 0.07 lb 43
2002-07-08 Standard trap nets 9.1 (above normal) 1.5 – 9.1 0.07 lb 82
2022-08-01 Standard gill nets 0.3 — 0.20 lb 3
2022-08-01 Standard trap nets 1.6 (normal) 1.5 – 9.1 0.30 lb 13
1987-07-08 Standard gill nets 4.8 — 0.15 lb 19
1987-07-08 Standard trap nets 2.6 (normal) 1.5 – 9.1 0.16 lb 26
1997-07-14 Standard gill nets 2.3 — 0.08 lb 14
1997-07-14 Standard trap nets 2.2 (normal) 1.5 – 9.1 0.13 lb 20
2012-07-30 Standard gill nets 1.9 — 0.32 lb 17
2012-07-30 Standard trap nets 4.1 (normal) 1.5 – 9.1 0.29 lb 37
2012-07-30 15-ft beach seine 0.2 — — 1

Walleye

Date Gear CPUE Normal Range Avg Weight Total Catch
1992-07-22 Standard gill nets 4.8 (normal) 1.2 – 5.3 2.07 lb 29
1992-07-22 Standard trap nets 0.4 (normal) 0.3 – 0.8 2.90 lb 4
1982-06-23 Standard gill nets 1.8 (normal) 1.2 – 5.3 4.25 lb 7
2007-07-30 Standard gill nets 6.4 (above normal) 1.2 – 5.3 0.79 lb 58
2007-07-30 Standard trap nets 0.3 (normal) 0.3 – 0.8 2.62 lb 3
2002-07-08 Standard gill nets 3.7 (normal) 1.2 – 5.3 0.84 lb 33
2002-07-08 Standard trap nets 1.2 (above normal) 0.3 – 0.8 2.83 lb 11
2022-08-01 Standard gill nets 7.6 (above normal) 1.2 – 5.3 1.00 lb 68
2022-08-01 Standard trap nets 0.4 (normal) 0.3 – 0.8 1.62 lb 3
1987-07-08 Standard gill nets 4.0 (normal) 1.2 – 5.3 1.75 lb 16
1987-07-08 Standard trap nets 0.3 (normal) 0.3 – 0.8 0.40 lb 3
1997-07-14 Standard gill nets 3.5 (normal) 1.2 – 5.3 2.39 lb 21
1997-07-14 Standard trap nets 0.2 (below normal) 0.3 – 0.8 0.62 lb 2
2012-07-30 Standard gill nets 3.3 (normal) 1.2 – 5.3 1.25 lb 30
2012-07-30 Standard trap nets 0.3 (normal) 0.3 – 0.8 1.11 lb 3

Black Bullhead

Date Gear CPUE Normal Range Avg Weight Total Catch
1992-07-22 Standard gill nets 0.5 (below normal) 3.1 – 47.6 0.83 lb 3
1982-06-23 Standard gill nets 8.3 (normal) 3.1 – 47.6 0.48 lb 33
1982-06-23 Standard trap nets 26.5 (normal) 1.0 – 29.9 0.55 lb 265
1987-07-08 Standard trap nets 2.8 (normal) 1.0 – 29.9 0.39 lb 28
1987-07-08 Standard gill nets 17.5 (normal) 3.1 – 47.6 0.44 lb 70
2012-07-30 Standard gill nets 0.1 (below normal) 3.1 – 47.6 0.35 lb 1

Brown Bullhead

Date Gear CPUE Normal Range Avg Weight Total Catch
1992-07-22 Standard gill nets 0.8 (normal) 0.5 – 5.5 0.74 lb 5
1987-07-08 Standard trap nets 3.9 (normal) 0.6 – 5.2 0.41 lb 39
1987-07-08 Standard gill nets 16.3 (above normal) 0.5 – 5.5 0.45 lb 65
1997-07-14 Standard trap nets 0.2 (below normal) 0.6 – 5.2 1.04 lb 2
2012-07-30 Standard trap nets 0.1 (below normal) 0.6 – 5.2 0.24 lb 1

CNM

Date Gear CPUE Normal Range Total Catch
2017-08-02 Backpack electrofishing 1.7 — 2

Johnny Darter

Date Gear CPUE Normal Range Total Catch
2017-08-02 Backpack electrofishing 4.3 — 5
2017-08-02 15-ft beach seine 0.3 — 1
2017-08-02 50-ft beach seine 0.5 — 3
2012-07-30 15-ft beach seine 0.2 — 1
2012-07-30 Backpack electrofishing 1.8 — 1

Tadpole Madtom

Date Gear CPUE Normal Range Total Catch
2017-08-02 Backpack electrofishing 2.6 — 3
2017-08-02 15-ft beach seine 1.0 — 4
2017-08-02 50-ft beach seine 0.2 — 1

Iowa Darter

Date Gear CPUE Normal Range Total Catch
2017-08-02 15-ft beach seine 14.0 — 56
2017-08-02 50-ft beach seine 2.8 — 17
2017-08-02 Backpack electrofishing 32.8 — 38
2012-07-30 15-ft beach seine 0.4 — 2
2012-07-30 Backpack electrofishing 5.3 — 3

Bluntnose Minnow

Date Gear CPUE Normal Range Total Catch
2017-08-02 50-ft beach seine 41.3 — 248
2017-08-02 Backpack electrofishing 79.3 — 92
2017-08-02 15-ft beach seine 24.0 — 96
2012-07-30 15-ft beach seine 23.4 — 117
2012-07-30 Backpack electrofishing 323.6 — 185
2012-07-30 50-ft beach seine 352.0 — 352

BKF

Date Gear CPUE Normal Range Total Catch
2017-08-02 50-ft beach seine 0.5 — 3
2017-08-02 Backpack electrofishing 5.2 — 6
2017-08-02 15-ft beach seine 2.3 — 9
2012-07-30 15-ft beach seine 0.8 — 4
2012-07-30 Backpack electrofishing 3.5 — 2

Golden Shiner

Date Gear CPUE Normal Range Total Catch
2017-08-02 Backpack electrofishing 0.9 — 1

Logperch

Date Gear CPUE Normal Range Total Catch
2017-08-02 Backpack electrofishing 0.9 — 1

BCS

Date Gear CPUE Normal Range Total Catch
2017-08-02 Backpack electrofishing 2.6 — 3

Fathead Minnow

Date Gear CPUE Normal Range Total Catch
2017-08-02 Backpack electrofishing 0.9 — 1

Rock Bass

Date Gear CPUE Normal Range Avg Weight Total Catch
2007-07-30 Standard trap nets 0.1 (below normal) 0.3 – 1.0 0.04 lb 1
2002-07-08 Standard gill nets 0.1 (below normal) 0.3 – 1.1 0.07 lb 1
2022-08-01 Standard trap nets 0.1 (below normal) 0.3 – 1.0 0.52 lb 1
2012-07-30 Standard trap nets 0.4 (normal) 0.3 – 1.0 0.28 lb 4

Hybrid Sunfish

Date Gear CPUE Normal Range Avg Weight Total Catch
2002-07-08 Standard trap nets 0.1 — 0.25 lb 1
2012-07-30 Backpack electrofishing 1.8 — — 1

BNS

Date Gear CPUE Normal Range Total Catch
2012-07-30 15-ft beach seine 0.6 — 3
2012-07-30 Backpack electrofishing 5.3 — 3
2012-07-30 50-ft beach seine 1.0 — 1

Depth Maps & Lake Info

View on MN DNR LakeFinder

Map & Directions

Get Directions

Showing 14 nearby bait & tackle shops on the map.

Nearby Bait & Tackle

Delaney's Outdoors

Park Rapids, MN

(218) 732-4281

★ 4.4

Killer Adventures

Park Rapids, MN

(701) 219-4332

★ 5

L&M Fleet Supply

Park Rapids, MN

(218) 732-4465

★ 4.6

North Country Bait

Park Rapids, MN

(218) 732-7500

★ 5

Northern Bait Co

Park Rapids, MN

(218) 732-5113

★ 4.6

Chad Zbasnik Fishing

Walker, MN

(218) 252-5363

Dean's Bait, Walker

Walker, MN

(218) 547-2248

★ 4.8

Fleet Supply

Wadena, MN

(218) 631-1660

★ 4.6

Nearby Marinas

Bob's Boat Storage

Laporte, MN

(218) 224-2505

★ 4.8

Boon-Docks Dock & Lift Sales

Bemidji, MN

(218) 766-9794

★ 5

Charlie's Boat & Marine LLC

Park Rapids, MN

(218) 732-3451

★ 4.6

Dan's All Season Service Inc.

Park Rapids, MN

(218) 237-3267

★ 4

Darrel's Small Eng ATV & Marine

Park Rapids, MN

(218) 732-8995

★ 4.8

Johnson’s On The Water Service

Park Rapids, MN

(218) 732-0798

★ 4.7

Resorts & Lodges Near Big Stony

Plan your stay — fishing resorts and lodges near Big Stony.

Birch Harbor Resort
Fishing Resort Park Rapids

(218) 732-3760
New Frontier Resort
Fishing Resort Park Rapids

(800) 932-3643
Balsam Beach Resort & RV Park
Fishing Resort Bemidji

(218) 751-5057
Cedar Shores Lodge & Resort
Fishing Resort Park Rapids

(218) 732-4626

View all 888 Minnesota resorts →

Fish Species

Species known to inhabit Big Stony. Click any species for a full fishing guide.

Black BullheadBlack CrappieBluegillLargemouth BassNorthern PikePumpkinseedRock BassWalleyeWhite SuckerYellow BullheadYellow Perch

Fishing Guides Near Big Stony

Baldy’s Mostly Musky Guide Service
Fishing Guide

(218) 252-3063
Go Fish! Guide Service
Fishing Guide

2182522278
Northwoods Guide Service
Fishing Guide

(651) 226-7555
Skiez Outdoors Guide Service
Fishing Guide

(320) 360-0710
Unparalleled Guide Service and Photography
Fishing Guide

(218) 209-9679
You Bet! Fishing Guide Service
Fishing Guide

(218) 308-8695

Other Lakes in Hubbard County

2nd Little Gulch

19.02 acres

Alice

126.91 acres

Bad Axe

303.26 acres

Belle Taine

1,496.66 acres

Benedict

464.36 acres

Big Bass

132.5 acres

Plan Your Trip to Big Stony

Data sourced from Minnesota DNR Division of Fish and Wildlife. Last verified: March 19, 2026. Learn how we maintain this data.