From the trailhead (Photo #1), walk through the forest on the great trail for 1.25 miles. Leave the forest and weave through bushes to reach a more-open area at 11,200’ where you’ll get your first view of Mt. Oklahoma, to the west - Photo #2. Follow the trail to the other side of a meadow and reach a trail junction at 11,200’ - Photo #3. Turning right would take you up the 14er Mt Massive - continue west on the North Halfmoon Lakes trail. After hiking back into the trees, pass a long rock-slab (Photo #4) to reach a clearing where you’ll get another look at Oklahoma - Photo #5. Continue up to 11,600’ to a flat, rocky overlook - Photo #6. Just after the overlook, it’s time to leave the North Halfmoon Lakes trail - Photo #7. The remainder of your climb will be off-trail.
Hike west into the dense forest and reach the 1st of two stream crossings less than 0.1 mile after leaving the trail - Photo #8. Cross the stream and continue west for another 0.1 mile to reach the 2nd and larger stream crossing - Photo #9. At this point you should be between 11,600’ and 11,700’ of elevation. If you’re above 11,700’ and the 2nd stream crossing has steep rock on the other side, descend a bit before crossing to easier terrain. After crossing, contour southwest for approx. 150 yards before turning right and ascending west up a subtle ridge (still in the forest) that leads to Oklahoma’s southeast slopes. Exit the forest near 11,900’ - Photo #10.
Continue west/northwest past some rock out-croppings (Photo #11) to reach the entrance of a high basin on Oklahoma’s southeast slopes - Photo #12 and Photo #13. Study your map, photos and GPS (if you brought one) to make sure you’re at the high basin and not off-route. Follow a drainage to 12,700’ and locate a steep, grassy slope to your right (north) - Photo #14. Climb the slope (Photo #15) to reach 13,100’ on a ridge, just east of the summit. Turn left (Photo #16) and hike up the easy, talus-covered ridge (Photo #17) to reach the summit - Photo #18, Photo #19 and Photo #20.