                         - - NOTES ON USAGE - -

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 THE DRAINAGE SYSTEM DIAGRAMS(S) THAT FOLLOW DISPLAY THEIR COMPONENT
 REACHES IN UPSTREAM ORDER, PROGRESSING FROM THEIR MOST DOWNSTREAM REACH
 TO THEIR MOST UPSTREAM REACH.  REACHRET LINKS THE DRAINAGE SYSTEMS OF
 CATALOGING UNITS THAT ARE HYDROLOGICALLLY CONNECTED AND PRESENTS THEM
 AS A SINGLE DRAINAGE SYSTEM.  CATALOGING UNITS THAT ARE NOT
 HYDROLOGICALLY CONNECTED ARE PRESENTED AS SEPARATE DRAINAGE SYSTEMS.

 A DESCRIPTION OF EVERY REACH WITHIN EACH DRAINAGE SYSTEM DISPLAYED
 APPEARS TO THE RIGHT OF THE DRAINAGE SYSTEM DIAGRAM.  HOWEVER, ONLY
 HYDROLOGICALLY CONNECTED REACHES, I.E., TRANSPORT REACHES, ARE
 DISPLAYED IN THE DIAGRAM ITSELF.

 THE PREFIX OF EACH REACH DESCRIPTION CAN BE USED TO IDENTIFY TRANSPORT
 AND ASSOCIATED SHORELINE REACHES.  THE PREFIXES SERVE AS AN AID IN
 DETERMINING THE REACHES THAT WILL BE SELECTED DURING STORET
 HYDROLOGICAL RETRIEVALS (STORET HYDROLOGICAL RETRIEVALS RETRIEVE ONLY
 TRANSPORT AND ASSOCIATED SHORELINE REACHES).  THE PREFIXES FOR
 TRANSPORT REACH DESCRIPTIONS ARE  @@, ==, <<, AND >>.  ASSOCIATED
 SHORELINE REACH DESCRIPTIONS ARE PREFIXED BY A PLUS SIGN (+) AND
 NON-ASSOCIATED SHORELINE AND ISOLATED REACH DESCRIPTIONS BY A MINUS
 SIGN (-).

 FOR PURPOSES OF IDENTIFICATION, UNKNOWN REACH NAMES ARE ASSIGNED
 FICTICIOUS NAMES OF THE FORM *X (WHERE X IS A LETTER OF THE ALPHABET).

 REACH TYPE CODES DISPLAYED BELOW ARE DEFINED, AS FOLLOWS:
   A,M,V       OPEN WATER REACH.
     B         BI-DIRECTIONAL REACH.
     C         COASTLINE.
     E         ENTRY REACH.
     G         GREAT LAKES SHORELINE.
     I         ISLAND SHORELINE.
     L         LAKE (OTHER THAN GREAT LAKE) OR RESERVOIR SHORELINE.
     N         ISOLATED REACH.
     R         REGULAR REACH.
     S         SOURCE OR HEADWATERS REACH.
     T         TERMINAL REACH.
     W         WIDE RIVER SHORELINE.
     X         SOURCE AND TERMINAL REACH.
     Z         TERMINAL AND ENTRY REACH.

 WHEN NO DIGITIZED REACH TRACE IS AVAILABLE, THE TEXT 'NO TRACE' IS
 PRINTED UNDER THE COLUMN THAT OTHERWISE CONTAINS THE REACH UPSTREAM
 LATITUDE-LONGITUDE.  FOR ALL OTHER MISSING OR UNKNOWN ITEMS A QUESTION
 MARK (?) IS PRINTED.

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 REFERENCE THE DATASET NAMED 'STORET.HELP.REACH.RETRIEVL' FOR A DETAILED
 DESCRIPTION OF REACH FILE CONCEPTS AND A COMPREHENSIVE DISCUSSION OF
 STORET RETRIEVAL CAPABILITIES ASSOCIATED WITH REACH FILE IDENTIFIERS.
