Deschutes County sells great detailed maps. Get the Bend and Crescent Ranger District.
From Mt. Bach or Wanoga, either ride to Cultus Lake on the highway, go over Kwolh/Sheridan Mountain (grooomed), or the easy way, south to trail 3 (4025) which is the easiest and fastest way to the Cascades Highway.
Enter Cultus Lake road to trail 55 on left to the Waldo Road. You can also go to Little Cultus Lake and up to Waldo Lake. At the top, go left 2X to the road back down. These trials are not groomed or even ridden.
Take Cross District to Davis Lake and cross over to Crescent Lake (snowpark), food and fuel. Then around Crescent Lake to the trail to Summitt Lake and Diamond Lake.