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_20613 ( "Missouri vs." text, "Overall Record" text, "at Columbia" text, "at Opponents Venue" text, "at Neutral Site" text, "Last 5 Meetings" text, "Last 10 Meetings" text, "Current Streak" text, "During Time in Big 12" text )

### Question ###
Name the total number of opponets venue for oklahoma

### Accurate SQL ###

SELECT COUNT("at Opponents Venue") FROM table_20613 WHERE "Missouri vs." = 'Oklahoma'