If you are VFR, why not just plan to enter the pattern for your choice runway for wind. Grand Canyon rwy 03 is left traffic and rwy 21 is right traffic. If visiblility is good, all you need to know is runway elevation, length and the aforementioned. Ex: Enter downwind at pattern altitude and state your intentions. You can also enter the pattern on the crosswind leg, base leg or straight in. Entering downwind is the preferred method for VFR but you can utilize the other methods as well, especially if there is no traffic.
If you are shooting an ILS then, rwy 03 is the way to go or you can attempt a (non-published) localizer back course when landing rwy 21. You would have to rely on the VASI since there are no approach lights for rwy 21.