This video chronicles a hike up the Rush Creek Trail as far as Gem Lake.  Agnew Lake and Gem Lake are used as reservoirs for the Rush Creek Hydroelectric Project's powerhouse, which is located below, near Silver Lake.  The Rush Creek Trail starts at the Silver Lake Resort and Campground, and ultimately enters the Ansel Adams Wilderness Area, where it connects with the famous Pacific Crest and John Muir Trail, with Yosemite National Park just to the north, and the Ritter Range area to the south.

 

 

 

Thanks to @JoshuaASharp  for this video.