Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_66586 ( "School" text, "Location" text, "Mascot" text, "Enrollment" real, "IHSAA Class" text, "# / County" text, "Year Joined" real )

### Question ###
what is the enrollement for the year joined 1958 in clarksville?

### Accurate SQL ###

SELECT SUM("Enrollment") FROM table_66586 WHERE "Year Joined" = '1958' AND "Location" = 'clarksville'