I must have it saved somewhere but it was nowhere to be found. The password was lost. My root account was forever secure--or was it?

# service mariadb stop
# mysqld_safe --skip-grant-tables &
# mysql -u root
> USE mysql
> UPDATE user SET password=PASSWORD("mynewpassword") WHERE User='root';
> FLUSH PRIVILEGES
> QUIT

This didn't stop the mysqld_safe process, so I killed the parent mysql process (/usr/libexec/mysqld) via its process ID ($pid).

# kill $pid

Start MySQL back up.

# service mariadb start

Finally, for security purposes, remove the UPDATE user ... SQL statement from ~/.mysql_history.

Profit! And don't forget to securely store your password.