The Securities and Exchange Commission has not necessarily reviewed the information in this filing and has not determined if it is accurate and complete.
The reader should not assume that the information is accurate and complete.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM 13F

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number: 3235-0006
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COLUMN 1 COLUMN 2 COLUMN 3 COLUMN 4 COLUMN 5 COLUMN 6 COLUMN 7 COLUMN 8
VALUE SHRS OR SH/ PUT/ INVESTMENT OTHER VOTING AUTHORITY
NAME OF ISSUER TITLE OF CLASS CUSIP (x$1000) PRN AMT PRN CALL DISCRETION MANAGER SOLE SHARED NONE
Abbott Laboratories COM 002824100 255,102 4,257,369 SH   SOLE   3,355,015 0 902,353
Abbvie Inc COM 00287Y109 16,546 174,811 SH   SOLE   40,524 0 134,287
Actuant Corp COM 00508X203 11,085 476,775 SH   SOLE   476,775 0 0
Adobe Systems COM 00724F101 454 2,100 SH   SOLE   0 0 2,100
Agree Realty Corp COM 008492100 4,357 90,699 SH   SOLE   89,199 0 1,500
ALLETE, Inc. COM 018522300 12,430 172,043 SH   SOLE   116,600 0 55,443
Alliant Energy Corp. COM 018802108 295 7,228 SH   SOLE   0 0 7,228
Alphabet Inc Class A COM 02079K305 1,398 1,348 SH   SOLE   617 0 731
Alphabet Inc Class C COM 02079K107 213,360 206,786 SH   SOLE   178,585 0 28,201
Altria Group Inc COM 02209S103 449 7,207 SH   SOLE   413 0 6,794
Amazon Com Inc COM 023135106 848 586 SH   SOLE   0 0 586
American Express COM 025816109 124,307 1,332,618 SH   SOLE   1,036,571 0 296,047
American Tower Cl A COM 03027X100 457 3,145 SH   SOLE   0 0 3,145
Ameriprise Financial COM 03076C106 345 2,331 SH   SOLE   90 0 2,241
Ametek Inc. COM 031100100 205 2,700 SH   SOLE   2,700 0 0
Amgen COM 031162100 1,696 9,948 SH   SOLE   1,400 0 8,548
Apogee Enterprises, Inc COM 037598109 14,086 324,930 SH   SOLE   323,630 0 1,300
Apple Computer COM 037833100 5,233 31,188 SH   SOLE   6,973 0 24,215
Applied Materials Inc COM 038222105 463 8,327 SH   SOLE   0 0 8,327
Assoc Banc Corp COM 045487105 67,679 2,723,484 SH   SOLE   2,298,543 0 424,941
AT&T COM 00206R102 1,556 43,654 SH   SOLE   1,165 0 42,489
Autoliv Inc COM 052800109 279 1,910 SH   SOLE   0 0 1,910
Automatic Data Proc COM 053015103 573 5,052 SH   SOLE   1,850 0 3,202
Badger Meter Inc COM 056525108 78,682 1,668,760 SH   SOLE   1,289,620 0 379,140
Bank of America Corp COM 060505104 376 12,538 SH   SOLE   0 0 12,538
Baxter International COM 071813109 52,593 808,632 SH   SOLE   482,978 0 325,654
Becton Dickinson & Co COM 075887109 888 4,096 SH   SOLE   1,267 0 2,829
Bemis COM 081437105 178,045 4,091,105 SH   SOLE   3,124,349 0 966,756
Berkshire Hathaway COM 084670108 2,991 10 SH   SOLE   0 0 10
Berkshire Hathaway B COM 084670702 4,357 21,842 SH   SOLE   1,625 0 20,217
Bio-Techne Corp COM 09073M104 208,185 1,378,347 SH   SOLE   1,106,776 0 271,571
Biogen Inc. COM 09062X103 281 1,025 SH   SOLE   0 0 1,025
Black Hills Corp COM 092113109 9,834 181,110 SH   SOLE   181,110 0 0
Boeing COM 097023105 1,230 3,752 SH   SOLE   1,465 0 2,287
BP PLC COM 055622104 1,284 31,672 SH   SOLE   5,534 0 26,138
Bristol-Myers Squibb COM 110122108 18,463 291,902 SH   SOLE   175,897 0 116,005
C H Robinson Worldwide COM 12541W209 179,493 1,915,406 SH   SOLE   1,476,104 0 439,302
Calyxt Inc COM 13173L107 2,763 210,609 SH   SOLE   210,609 0 0
Cardinal Health COM 14149Y108 203 3,244 SH   SOLE   1,458 0 1,786
Cardiovascular Sys Inc COM 141619106 1,780 81,162 SH   SOLE   81,162 0 0
Casey's General Stores COM 147528103 11,954 108,900 SH   SOLE   108,900 0 0
Catalent, Inc. COM 148806102 14,098 343,363 SH   SOLE   342,760 0 603
Caterpillar COM 149123101 1,104 7,490 SH   SOLE   0 0 7,490
Celgene Corp COM 151020104 270 3,030 SH   SOLE   0 0 3,030
Centerpoint Energy Inc COM 15189T107 211 7,709 SH   SOLE   0 0 7,709
Cerner Corp COM 156782104 258 4,455 SH   SOLE   0 0 4,455
Charles Schwab COM 808513105 35,452 678,902 SH   SOLE   441,460 0 237,442
Chevron Corp COM 166764100 40,928 358,890 SH   SOLE   170,378 0 188,512
Cisco COM 17275R102 1,449 33,784 SH   SOLE   2,716 0 31,068
Clorox COM 189054109 201 1,513 SH   SOLE   1,350 0 163
Coca-Cola COM 191216100 1,363 31,385 SH   SOLE   9,325 0 22,060
Colgate-Palmolive COM 194162103 663 9,247 SH   SOLE   0 0 9,247
Comcast New Cl A COM 20030N101 274 8,014 SH   SOLE   654 0 7,360
ConocoPhillips COM 20825C104 7,925 133,673 SH   SOLE   10,262 0 123,411
CoreSite Realty Corp COM 21870Q105 69,994 698,123 SH   SOLE   625,115 0 73,008
Corning COM 219350105 65,911 2,364,095 SH   SOLE   1,866,867 0 497,228
Costco Wholesale COM 22160K105 654 3,472 SH   SOLE   600 0 2,872
Cray Inc COM 225223304 48,469 2,341,497 SH   SOLE   1,905,760 0 435,737
CSX Corporation COM 126408103 513 9,200 SH   SOLE   0 0 9,200
Cullen Frost Bankers COM 229899109 13,781 129,920 SH   SOLE   129,270 0 650
CyberOptics Corp COM 232517102 4,799 266,600 SH   SOLE   266,600 0 0
Deere & Co. COM 244199105 247 1,592 SH   SOLE   112 0 1,480
Deluxe Corp COM 248019101 4,728 63,880 SH   SOLE   0 0 63,880
Disney COM 254687106 201,093 2,002,124 SH   SOLE   1,592,493 0 409,631
Dominion Energy, Inc. COM 25746U109 245 3,632 SH   SOLE   0 0 3,632
Donaldson COM 257651109 248,733 5,521,259 SH   SOLE   4,287,602 0 1,233,657
DowDupont Inc. COM 26078J100 935 14,671 SH   SOLE   0 0 14,671
Ecolab Inc COM 278865100 373,658 2,726,038 SH   SOLE   2,098,382 0 627,656
EMC Insurance Group COM 268664109 5,159 190,528 SH   SOLE   190,528 0 0
Emerson Electric COM 291011104 36,850 539,534 SH   SOLE   177,685 0 361,849
Exelon Corp COM 30161N101 543 13,928 SH   SOLE   0 0 13,928
Exxon Mobil COM 30231G102 54,333 728,221 SH   SOLE   275,120 0 453,101
Facebook Inc Class A COM 30303M102 217 1,361 SH   SOLE   384 0 977
Fastenal Co. COM 311900104 163,890 3,002,204 SH   SOLE   2,323,905 0 678,299
Fedex Corp. COM 31428X106 718 2,990 SH   SOLE   0 0 2,990
Fiserv COM 337738108 147,361 2,066,481 SH   SOLE   1,578,256 0 488,225
Fleetcor Technologies Inc COM 339041105 203 1,000 SH   SOLE   0 0 1,000
Generac Hldgs COM 368736104 39,108 851,835 SH   SOLE   755,776 0 96,059
General Electric COM 369604103 28,972 2,149,229 SH   SOLE   1,167,552 0 981,677
General Mills COM 370334104 142,566 3,163,917 SH   SOLE   2,276,269 0 887,648
Gentherm Inc COM 37253A103 28,468 838,525 SH   SOLE   777,478 0 61,047
Glacier Bancorp Inc COM 37637Q105 14,129 368,130 SH   SOLE   367,760 0 370
Graco Inc COM 384109104 280,269 6,130,112 SH   SOLE   4,405,840 0 1,724,272
Great Western Bancorp Inc. COM 391416104 88,156 2,189,133 SH   SOLE   1,850,158 0 338,975
Hawkins Chemical COM 420261109 4,763 135,500 SH   SOLE   129,000 0 6,500
HB Fuller COM 359694106 148,365 2,983,408 SH   SOLE   2,491,247 0 492,161
Hershey COM 427866108 12,649 127,823 SH   SOLE   91,795 0 36,028
Home Depot COM 437076102 61,702 346,171 SH   SOLE   196,719 0 149,452
Honeywell Inc COM 438516106 299,665 2,073,663 SH   SOLE   1,537,488 0 536,175
Hormel COM 440452100 239,658 6,983,031 SH   SOLE   5,464,736 0 1,518,295
Hub Group Inc Cl A COM 443320106 9,210 220,080 SH   SOLE   220,080 0 0
IBM COM 459200101 18,704 121,905 SH   SOLE   49,847 0 72,058
IDEXX Laboratories, Inc COM 45168D104 823 4,298 SH   SOLE   0 0 4,298
Illinois Tool Works Inc COM 452308109 572 3,649 SH   SOLE   0 0 3,649
Intel COM 458140100 21,161 406,322 SH   SOLE   62,595 0 343,727
Intl Flavors/Fragr COM 459506101 338 2,466 SH   SOLE   2,000 0 466
Intricon Corp Com COM 46121H109 2,188 109,400 SH   SOLE   109,400 0 0
IPG Photonics Corp COM 44980X109 467 2,000 SH   SOLE   0 0 2,000
J.P. Morgan Chase & Co COM 46625H100 27,523 250,279 SH   SOLE   149,369 0 100,910
Johnson & Johnson COM 478160104 284,710 2,221,696 SH   SOLE   1,678,244 0 543,452
Kellogg COM 487836108 276 4,250 SH   SOLE   0 0 4,250
Kimberly-Clark COM 494368103 23,321 211,758 SH   SOLE   88,480 0 123,278
Lilly (Eli) COM 532457108 80,410 1,039,293 SH   SOLE   742,992 0 296,301
LittleFuse Inc. COM 537008104 15,655 75,200 SH   SOLE   75,200 0 0
Lockheed Martin Corp COM 539830109 329 974 SH   SOLE   494 0 480
Lowes Companies Inc COM 548661107 471 5,369 SH   SOLE   0 0 5,369
Marcus Corp. COM 566330106 10,168 335,023 SH   SOLE   335,023 0 0
Marsh & McLennan COM 571748102 204 2,466 SH   SOLE   1,000 0 1,466
MasterCard Inc COM 57636Q104 463 2,645 SH   SOLE   0 0 2,645
McDonald's Corp COM 580135101 2,424 15,504 SH   SOLE   11,000 0 4,504
MDU Resources Group COM 552690109 3,276 116,319 SH   SOLE   950 0 115,369
Medtronic COM G5960L103 294,287 3,668,495 SH   SOLE   2,836,822 0 831,673
Merck & Co Inc COM 58933Y105 5,083 93,321 SH   SOLE   12,244 0 81,077
Microsoft COM 594918104 74,402 815,184 SH   SOLE   618,914 0 196,270
MMM Co. COM 88579Y101 310,392 1,413,957 SH   SOLE   924,114 0 489,843
MTS Systems COM 553777103 1,801 34,875 SH   SOLE   3,300 0 31,575
Neogen Corp COM 640491106 252 3,765 SH   SOLE   0 0 3,765
NextEra Energy, Inc. COM 65339F101 450 2,753 SH   SOLE   0 0 2,753
Nike COM 654106103 292 4,400 SH   SOLE   1,200 0 3,200
Norfolk Southern Corp COM 655844108 721 5,310 SH   SOLE   145 0 5,165
Novartis COM 66987V109 263 3,250 SH   SOLE   800 0 2,450
NVE Corp COM 629445206 34,630 416,674 SH   SOLE   368,319 0 48,355
NW Biotherapeutics COM 66737P600 3 12,500 SH   SOLE   0 0 12,500
Oasis Petroleum Inc COM 674215108 4,227 521,820 SH   SOLE   521,820 0 0
Old Natl Bancorp Ind Com COM 680033107 5,303 313,793 SH   SOLE   313,793 0 0
Oracle Sys COM 68389X105 1,475 32,242 SH   SOLE   447 0 31,795
Oshkosh Corp COM 688239201 12,429 160,857 SH   SOLE   160,790 0 67
Otter Tail Power COM 689648103 304 7,008 SH   SOLE   0 0 7,008
Patterson Companies COM 703395103 38,999 1,754,348 SH   SOLE   1,294,324 0 460,024
Paychex COM 704326107 265 4,297 SH   SOLE   0 0 4,297
Pentair PLC COM G7S00T104 167,454 2,457,855 SH   SOLE   1,823,756 0 634,099
PepsiCo Inc COM 713448108 1,491 13,659 SH   SOLE   1,220 0 12,439
Pfizer Inc COM 717081103 150,019 4,227,070 SH   SOLE   3,214,093 0 1,012,977
Philip Morris Intl Inc COM 718172109 868 8,729 SH   SOLE   393 0 8,336
Phillips 66 COM 718546104 2,173 22,650 SH   SOLE   0 0 22,650
Physicians Realty Tr COM 71943U104 14,765 948,310 SH   SOLE   928,310 0 20,000
Polaris Ind COM 731068102 436 3,803 SH   SOLE   3,050 0 753
PPG Industries COM 693506107 225 2,020 SH   SOLE   1,000 0 1,020
Praxair COM 74005P104 296 2,051 SH   SOLE   0 0 2,051
Premier Inc Cl A COM 74051N102 9,031 288,439 SH   SOLE   288,439 0 0
Principal Financial COM 74251V102 156,850 2,575,112 SH   SOLE   2,027,271 0 547,841
Procter & Gamble COM 742718109 27,462 346,388 SH   SOLE   74,126 0 272,262
Proto Labs COM 743713109 42,804 364,132 SH   SOLE   299,481 0 64,651
PureCycle Corp COM 746228303 112 11,855 SH   SOLE   0 0 11,855
QCR Holdings COM 74727A104 4,080 90,975 SH   SOLE   90,975 0 0
Qualcomm, Inc. COM 747525103 75,460 1,361,840 SH   SOLE   1,126,008 0 235,832
Raven Industries Inc COM 754212108 5,680 162,066 SH   SOLE   161,566 0 500
Raytheon Co COM 755111507 297 1,375 SH   SOLE   0 0 1,375
Roche Hldg Ltd ADR COM 771195104 157,977 5,518,834 SH   SOLE   4,583,237 0 935,597
Royal Dutch Shell Spons ADR A COM 780259206 339 5,320 SH   SOLE   400 0 4,920
Schlumberger COM 806857108 142,751 2,203,625 SH   SOLE   1,726,825 0 476,800
SEI Investments Co COM 784117103 247 3,300 SH   SOLE   0 0 3,300
Shire PLC COM 82481R106 547 3,659 SH   SOLE   487 0 3,172
Snap-On Inc. COM 833034101 59,390 402,535 SH   SOLE   310,283 0 92,252
Southern Co. COM 842587107 240 5,367 SH   SOLE   150 0 5,217
SPS Commerce Inc COM 78463M107 1,062 16,570 SH   SOLE   16,320 0 250
Starbucks Corp COM 855244109 634 10,947 SH   SOLE   0 0 10,947
Stratasys Ltd COM M85548101 5,847 289,745 SH   SOLE   223,332 0 66,413
Sysco COM 871829107 256 4,272 SH   SOLE   0 0 4,272
Target COM 87612E106 111,162 1,601,065 SH   SOLE   1,063,612 0 537,452
TCF Financial COM 872275102 775 33,982 SH   SOLE   3,828 0 30,154
Tennant Company COM 880345103 81,193 1,199,312 SH   SOLE   1,012,828 0 186,484
Thermo Fisher Scientific COM 883556102 301 1,460 SH   SOLE   0 0 1,460
Tile Shop Inc COM 88677Q109 5,422 903,710 SH   SOLE   903,710 0 0
Toro COM 891092108 155,616 2,491,847 SH   SOLE   1,872,146 0 619,701
Travelers Cos Inc COM 89417E109 36,029 259,464 SH   SOLE   76,696 0 182,768
Union Pacific COM 907818108 1,243 9,244 SH   SOLE   1,800 0 7,444
United Bankshares Inc. COM 909907107 6,505 184,541 SH   SOLE   184,069 0 472
United Fire Group COM 910340108 10,557 220,572 SH   SOLE   220,572 0 0
United Health Group COM 91324P102 110,205 514,976 SH   SOLE   423,058 0 91,918
United Parcel Service COM 911312106 105,441 1,007,460 SH   SOLE   715,697 0 291,763
United Technologies COM 913017109 1,789 14,221 SH   SOLE   2,521 0 11,700
Urologix Inc COM 917273104 0 20,000 SH   SOLE   0 0 20,000
US Bancorp COM 902973304 337,760 6,688,312 SH   SOLE   5,232,761 0 1,455,551
Verizon Comm COM 92343V104 6,273 131,182 SH   SOLE   1,866 0 129,316
Visa, Inc COM 92826C839 7,488 62,596 SH   SOLE   56,154 0 6,442
Walgreen Boots Alliance COM 931427108 684 10,450 SH   SOLE   0 0 10,450
Walmart Inc COM 931142103 438 4,921 SH   SOLE   1,500 0 3,421
WEC Energy Group COM 92939U106 462 7,369 SH   SOLE   0 0 7,369
Wells Fargo & Co COM 949746101 134,104 2,558,751 SH   SOLE   1,774,356 0 784,395
Westamerica Bancorporation COM 957090103 311 5,359 SH   SOLE   0 0 5,359
Western Union COM 959802109 69,463 3,612,208 SH   SOLE   2,905,766 0 706,442
Weyerhaeuser COM 962166104 650 18,570 SH   SOLE   3,653 0 14,917
Wintrust Finan Corp COM 97650W108 14,377 167,080 SH   SOLE   167,080 0 0
Workiva Inc COM 98139A105 6,499 274,223 SH   SOLE   274,223 0 0
Xcel Energy Inc. COM 98389B100 12,971 285,204 SH   SOLE   107,618 0 177,586
Zimmer Biomet Holdings, Inc. COM 98956P102 120,765 1,107,532 SH   SOLE   856,841 0 250,691
Zoetis Inc. COM 98978V103 346 4,140 SH   SOLE   0 0 4,140
iShares Core S&P 500 ETF ETF 464287200 1,185 4,464 SH   SOLE   0 0 4,464
iShares Core S&P Midcap ETF ETF 464287507 400 2,130 SH   SOLE   0 0 2,130
iShares MSCI EAFE Fd ETF 464287465 523 7,506 SH   SOLE   967 0 6,539
iShares Russell 1000 Growth ETF 464287614 891 6,545 SH   SOLE   0 0 6,545
iShares Russell 1000 Value ETF 464287598 580 4,835 SH   SOLE   100 0 4,735
iShares Russell 2000 ETF ETF 464287655 528 3,475 SH   SOLE   0 0 3,475
iShares Russell Midcap ETF ETF 464287499 709 3,435 SH   SOLE   0 0 3,435
iShares S&P Smallcap ETF 464287887 288 1,655 SH   SOLE   0 0 1,655
iShares Select Div ETF 464287168 711 7,479 SH   SOLE   45 0 7,434
Schwab Intl Eq ETF ETF 808524805 1,652 49,000 SH   SOLE   0 0 49,000
Schwab US Broad Mkt ETF ETF 808524102 2,894 45,370 SH   SOLE   0 0 45,370
SPDR S&P 500 ETF Trust ETF 78462F103 12,025 45,697 SH   SOLE   28,613 0 17,084
Vanguard Dividend App ETF ETF 921908844 324 3,204 SH   SOLE   0 0 3,204
Nuveen MN Qual Mun Income Fd COM 670734102 524 37,002 SH   SOLE   0 0 37,002
Nuveen Quality Muncp Income Fd COM 67066V101 162 12,323 SH   SOLE   2,150 0 10,173