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

FORM 13F COVER PAGE
OMB APPROVAL
OMB Number:3235-0006
Expires:July 31, 2015
Estimated average burden
hours per response:23.8
Report for the Calendar Year or Quarter Ended:
03-31-2021
Check here if Amendment: ☐ Amendment Number:
This Amendment (Check only one.):☐ is a restatement.
☐ adds new holdings entries.

Institutional Investment Manager Filing this Report:

Name:
MAD RIVER INVESTORS
Address:
84 STATE STREET
SUITE 1060
BOSTON, MA 02109
Form 13F File Number:
028-12322

The institutional investment manager filing this report and the person by whom it is signed hereby represent that the person signing the report is authorized to submit it, that all information contained herein is true, correct and complete, and that it is understood that all required items, statements, schedules, lists, and tables, are considered integral parts of this form.


Person Signing this Report on Behalf of Reporting Manager:
Name:
Stephen C Carluccio
Title:
Chief Compliance Officer
Phone:
617-728-0333


Signature, Place, and Date of Signing:

// Stephen C Carluccio //
                         [Signature]
Boston, MASSACHUSETTS
                 [City, State]
05-03-2021
                           [Date]
                          

Report Type (Check only one.):

☒ 13F HOLDINGS REPORT. (Check here if all holdings of this reporting manager are reported in this report.) 

☐ 13F NOTICE. (Check here if no holdings reported are in this report, and all holdings are reported by other reporting manager(s).) 

☐ 13F COMBINATION REPORT. (Check here if a portion of the holdings for this reporting manager are reported in this report and a portion are reported by other reporting manager(s).)


Form 13F Summary Page

Report Summary:

Number of Other Included Managers:
0
Form 13F Information table Entry Total:
23
Form 13F Information table Value Total:
150000
          (thousands)

List of Other Included Managers:

Provide a numbered list of the name(s) and Form 13F file number(s) of all institutional investment managers with respect to which this report is filed, other than the manager filing this report.
[If there are no entries in this list, state "NONE" and omit the column headings and list entries.]

  
NONE


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

FORM 13F INFORMATION TABLE
OMB APPROVAL
OMB Number:3235-0006
Expires:July 31, 2015
Estimated average burden
hours per response:23.8
COLUMN 1COLUMN 2COLUMN 3COLUMN 4COLUMN 5COLUMN 6COLUMN 7COLUMN 8
VALUESHRS ORSH/PUT/INVESTMENTOTHERVOTING AUTHORITY
NAME OF ISSUERTITLE OF CLASSCUSIP(x$1000)PRN AMTPRNCALLDISCRETIONMANAGERSOLESHAREDNONE
ASSOCIATED CAP GROUP INCCL A0455281064,541126,625SHSOLE 0 0 126,625
BOEING COCOM0970231052,2548,850SHSOLE 0 0 8,850
BERKSHIRE HATHAWAY INC DELCL B NEW0846707024,12316,139SHSOLE 0 0 16,139
CACI INTL INCCL A1271903046,18625,080SHSOLE 0 0 25,080
CBOE GLOBAL MKTS INCCOM12503M1081,16811,835SHSOLE 0 0 11,835
CME GROUP INCCOM12572Q1052,18510,699SHSOLE 0 0 10,699
CIVEO CORP CDACOM NEW17878Y2075,801378,925SHSOLE 0 0 378,925
DISNEY WALT COCOM2546871064432,400SHSOLE 0 0 2,400
FRANCO NEV CORPCOM3518581055,02040,065SHSOLE 0 0 40,065
LIBERTY MEDIA CORP DELCOM SER A FRMLA53122987052113,635SHSOLE 0 0 13,635
LIBERTY MEDIA CORP DELCOM SER C FRMLA5312298541,86142,981SHSOLE 0 0 42,981
HOWARD HUGHES CORPCOM44267D1074,52747,586SHSOLE 0 0 47,586
INTERCONTINENTAL EXCHANGE INCOM45866F1041,52213,625SHSOLE 0 0 13,625
LIBERTY BROADBAND CORPCOM SER A5303071077074,868SHSOLE 0 0 4,868
LIBERTY BROADBAND CORPCOM SER C5303073053,70324,661SHSOLE 0 0 24,661
LIBERTY MEDIA CORP DELCOM A SIRIUSXM53122940950811,520SHSOLE 0 0 11,520
LIBERTY MEDIA CORP DELCOM C SIRIUSXM5312296072,87665,197SHSOLE 0 0 65,197
MESABI TRCTF BEN INT5906721015,648187,750SHSOLE 0 0 187,750
NUVEEN AMT FREE QLTY MUN INCCOM67065710549033,097SHSOLE 0 0 33,097
RLI CORPCOM7496071077817,000SHSOLE 0 0 7,000
TEXAS PACIFIC LAND CORPORATICOM88262P10286,57054,466SHSOLE 0 0 54,466
MAMMOTH ENERGY SVCS INCCOM56155L1085710,700SHSOLE 0 0 10,700
WHEATON PRECIOUS METALS CORPCOM9628791028,508222,677SHSOLE 0 0 222,677