Cultus Lake is another easy ride especially if you just ride to the other end of the lake and back. There is no singletrack trail ALL the way around the lake. To do a loop you can ride to Little Cultus Lake and then ride back to the trailhead via Road #4630 (4 miles). At the beginning of the ride, there is a ton of dead or dying timber from beetle infestations. Consequently,every year there are many downed trees to cross until the trail is cleared. Typically, there are so many trees that you will regret doing the ride unless it has been cleared. Once cleared, the trail is actually a fun little ride. After you pass the campground on the west end of the lake, the trail climbs a bit on the way to Deer Lake.
Mosquitoes can be bad from Cultus Lake south, but not as bad as at Waldo Lake. If you go in the middle of the day, and keep riding, you can probably get by without bug dope.
Cultus is one of the few mountain lakes close to Bend where they allow speed boats. As Bend grows, it is becoming pretty crowded with boats and camping boaters. There is a campground at the west end of the lake that is only accessed by boat, making it a real special destination for power boaters.
This is all in National Forest so you will need a pass if that beloved program is still in effect. (They don't make any money on it. The cost to collect the fees and give tickets is at least as much as they take in.)
Directions to the trailhead: In Google Maps copy and paste "NF-120 @43.841420, -121.834590" as a destination.Cultus Lake Printable Broadband Map Experience