<?xml version="1.0" encoding="utf-8"?>
<schema
  xmlns="http://www.w3.org/2001/XMLSchema"
  xmlns:accounting="http://www.xbrl.org/2009/arcrole/accounting"
  xmlns:xbrli="http://www.xbrl.org/2003/instance"
  xmlns:link="http://www.xbrl.org/2003/linkbase"
  xmlns:xlink="http://www.w3.org/1999/xlink"
  xmlns:occ="http://xbrlsite.com/seattlemethod/occ"
  xmlns:xbrldt="http://xbrl.org/2005/xbrldt"
  xmlns:generic="http://xbrl.org/2008/generic"
  targetNamespace="http://xbrlsite.com/seattlemethod/occ"
  elementFormDefault="qualified" attributeFormDefault="unqualified">
  <annotation>
    <appinfo>
      <link:linkbaseRef xlink:type="simple" xlink:href="occ-lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Label Links, all" />
      <link:linkbaseRef xlink:type="simple" xlink:href="occ-ref.xml" xlink:role="http://www.xbrl.org/2003/role/referenceLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:title="Reference Links, all" />
    </appinfo>
  </annotation>
  <import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" />
  <import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd" />
  <import namespace="http://www.xbrl.org/2004/ref" schemaLocation="http://www.xbrl.org/2004/ref-2004-08-10.xsd" />
  <import namespace="http://www.xbrl.org/dtr/type/numeric" schemaLocation="http://www.xbrl.org/dtr/type/numeric-2009-12-16.xsd" />
  <import namespace="http://www.xbrl.org/dtr/type/non-numeric" schemaLocation="http://www.xbrl.org/dtr/type/nonNumeric-2009-12-16.xsd" />
  <import namespace="http://www.xbrl.org/2009/role/reference" schemaLocation="http://www.xbrl.org/lrr/role/reference-2009-12-16.xsd" />
  <import namespace="http://www.xbrlsite.com/seattlemethod/conceptual-model/cm-arcroles" schemaLocation="http://www.xbrlsite.com/seattlemethod/cm/cm-arcroles.xsd" />
  <import namespace="http://www.xbrl.org/2009/arcrole/accounting" schemaLocation="https://www.xbrl.org/lrr/arcrole/accounting-arcrole-2023-01-04.xsd" />
  <import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd" />
  <import namespace="http://www.w3.org/1999/xlink" schemaLocation="http://www.xbrl.org/2003/xlink-2003-12-31.xsd" />

  <element id="occ_Capital" name="Capital" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" />
  <element id="occ_CashAndDueFromBanks" name="CashAndDueFromBanks" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" />
  <element id="occ_Circulation" name="Circulation" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" />
  <element id="occ_Deposits" name="Deposits" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" />
  <element id="occ_HypercubeLineItems" name="HypercubeLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" abstract="true" nillable="true" />
  <element id="occ_Liabilities" name="Liabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" />
  <element id="occ_LiabilitiesRollUp" name="LiabilitiesRollUp" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" abstract="true" nillable="true" />
  <element id="occ_LoansIncludingOverdraft" name="LoansIncludingOverdraft" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" />
  <element id="occ_RealEstateFurnitureAndFixtures" name="RealEstateFurnitureAndFixtures" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" />
  <element id="occ_RedemptionFundWithUSTreasurer" name="RedemptionFundWithUSTreasurer" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" />
  <element id="occ_ReportToComptrollerHypercube" name="ReportToComptrollerHypercube" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" abstract="true" nillable="true" />
  <element id="occ_Resources" name="Resources" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" />
  <element id="occ_ResourcesRollUp" name="ResourcesRollUp" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" abstract="true" nillable="true" />
  <element id="occ_SurplusAndUndividedProfits" name="SurplusAndUndividedProfits" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" nillable="true" />
  <element id="occ_USBondsAndPremiums" name="USBondsAndPremiums" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" nillable="true" />
</schema>
