if your REALLY lucky (i.e. you have a friend that live on the like, or has proporty there) you get to ride at Triangle lake just outside of eugene, freakin nice area, my first ride was there, ah, the memories.
We ride at Fern Ridge during the week and early on weekend mornings (you want to be off the water by noon on Sat. and Sunday - gets real busy and can be windy). Dexter and Lookout Point just south east of Eugene on Hwy 58 are usually good on the weekends. Dexter is bottom fed from the Lookout Point dam so the water is cold, 65-70 in mid summer. Been to Loon Lake once but it is a 2+ hr drive from Corvallis. Loon is nice if you want to go and camp. It has a real nice BLM campground. Been to Triangle many times but it is small and packed on the weekends. Triangle is a great place to hang out and socialize - only good for riding/skiing mid-week and early, early morning. Foster and Green Peter outside of Sweet Home (45 min. east) can be good midweek but, like Fern Ridge, is a zoo on the weekends during the summer months. If you have some time and want to ride in gin clear water - take the 2 1/2 dr. to Crescent Lake. It is just past Willamette Pass Ski Area. Great camping but bring your wetsuits. Crescent is at 4900 ft. and spends a lot of it's life frozen over. Have fun and Go Beavers! John L.