I approached from Duffy lake Trailhead. As I did Red Butte on the this trip. http://www.pnwsota.org/blog/kf7sey/2021-july-12/red-butte-or-july-2021. This area requires a Central Cascades Wilderness Permit.
You could probally reach this one from Marion Lake via Marion Peak. There are some descriptions of others who have done it on summit post https://www.summitpost.org/saddle-mountain/742441
I Started from Blue Lake which is roughly 7 miles from trailhead and bushwack cross country for roughly a half mile to reach the ridge at a saddle between Green Peak and Saddle Mountain. once you reach the rigdge follow to summit. Class 3 maybe class 4 Rock Scramble required for 120 feet or so to summit. Summit is small and not a lot of room to setup and be confortable. Reminds me of a minture version of Mt Washington.