Take US 180 heading toward the Grand Canyon. Turn north on Schultz RD (FR 420). Turn left at the intersection with forest Rd 557. Continue on FR 420 for 6 miles Park near a pond, which is called Schultz tank. The trail is a blocked off road.
This Route can be done in one long day, but it recommended to take 2 days. The Trail is 8.7 miles to the intersection of the Humphreys trail. From there it's about 1/2 mile to the top of Humphreys Peak. The trail starts out winding up the backside of Fremont Peak. You can camp at the first Saddle you come to between Fremont Peak and Doyle Peak. The trail then goes into the Inner Basin and crosses Fremont Peak and zigzags across Agassiz. This route takes you away from the crowded Humphreys trail and is more scenic then the Humphreys trail. The trail is moderate to difficult. This route can also be used to hike Fremont Peak and Doyle Peak.
This route has the most elevation gain on Humphreys Peak with a rise of 4,609 feet.
If your doing a day hike, you just need a lot of water, and dress in layers, you never know what whether to expect. The top can be cold, and the bottom can be hot. Always anticipate the wind. If your Backpacking, you need a lot of water, there are no streams to fill your bottles up. Water filters are not needed since there are no streams or lakes.
A little about the Weatherford trail
The Weatherford Trail was once a road that led up to the ridge on Agassiz. From there People had access to hike up Agassiz Peak or hike over to Humphreys Peak and hike it. Now since they closed the road off to vehicles the road has eroded down to a little footpath that is only about a foot wide in places. Other parts of the trail it is evident that there was a road there at one time.
Sometime in the 80's the path up Agassiz Peak from the top of the Weatherford trail was closed off.