Agnew Meadows River Trail to Garnet Lake via the spur trail

[markskor]

Not knowing how many days you have planned for this adventure...
Suggest:
Day 1 - Agnew to River Trail/San Joaquin crossing. (~5 miles)...good starting/shakedown length first day.
Day 2 - Up to Garnet and, as camping is prohibited north end of Garnet (and lots of bear activity here), when you hit the Garnet exit bridge (River Trail terminus), go left and work your way along eastern shoreline use trail of Garnet south, and camp backside Garnet.
Day 3 - On the Southwest end of Garnet, a small stream enters Garnet (see TOPO) and a use trail starts (just behind a large rock at the stream exit) which leads over a small 300' knoll to the backside 1000 Island...easy. Plenty of camping sites backside 1000 Is and (as camping is also prohibited North side 1000 Is, a few sites up in the trees and bears congregate there too), camp backside 1000 Island...no people and no bears!
Day 4 - West side use trail going north - pick up the JMT, High Trail or River Trail again at the North end/ exit of 1000 Is and either go Tuolumne or return Agnew... it is all downhill back to Agnew.

You might also consider a zero day 1000 Is, maybe do Catherine, or just fish that day away - whatever.