After spending a few weeks with the Sigma 50mm ƒ/1.4 Art, I've come to realize maybe Sigma lenses aren't the solution for me. At least the 50mm has a very short focus throw, making manual focus a tedious process, even with focus aids like focus peaking and focus zoom. Autofocus is just too unreliable and slow to depend on for all occasions, making manual focus capability a priority.
A week before the Fremont hike, I grabbed a Shimoda Designs Explore 40 kit from Glazer's Camera. After transferring my gear from the LowePro to the Shimoda, I weighed it and it came out to only 24 lbs. Once I fully loaded the pack with extra clothes, food, water and the extra photography gear needed, it topped 42 lbs. Despite the extra weight, and with a pair of hiking poles, I made it up and down the mountain with my back in far better condition than the previous 2 weekends.