$re = '/Arvada( [a-zA-Z]+){0,4}[,\.] [A-Z]{2}/';
$str = 'City of Arvada\\n\\nRevenue Division\\nArvada, CO 80001\\n other random words';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php