We have done this like 3 times (https://williammartin.com/2018/09/10/off-the-beaten-path-in-the-park-osprey-falls/), but never the challenge (https://ridewithgps.com/routes/33087059). What is so different about the challenge, you ask? Well, normally to do Osprey Falls you just bike or hike from Mammoth. Super easy.
The challenge is to ride from the Yellowstone Gate in Gardiner all the way up Old Gardiner Road, through town in Mammoth, then up Bunsen Peak Trails to the trailhead of Osprey Falls. Then just do that super easy hike at the end.
Then ride back. Super cool, right?