You need to play things a bit safer than most students, but it's definitely do-able. Make sure you get a position with a firm the summer after 2L using the OPT or CPT programs. This should virtually ensure that you get hired after 3L; at that point, you'd just need to acquire a TN-1 visa before your F-1 expires.
Be prepared to stay with that firm for a few years. Once you have some experience, moving to different regions should become easier - however, that counts for most law school graduates.