Would you (or others) say the whole trail is doable without crampons or spikes?
Reservation is for this Saturday.
Thanks again to all!
It depends on how confident you are walking in hard snow. There are a couple of snow fields just above mirror lake before getting to trail camp and a couple on the switchbacks (see photos others have posted above) that you need to traverse. They have pretty solid tracks already laid down from all the hikers walking through them, so as long as you securely dig your heels in with each step, you should be fine. I should mention however that these snow fields are on a steep face so if you slip or lose you footing you could potentially slide down into the rocks below. This is where trekking poles can really help to stabilize yourself. Having crampons or spikes on would offer extra security as well.
Having said all that, my two buddies and I were able to do the entire hike from Whitney portal to the summit with only trekking poles and boots without crampons/spikes. If you have boots with good traction, you should be fine.
