When i lived in dixon about 15 years ago i used to fish lots of spots from stevensons bridge up to the winters dam and used to catch some really quality smallmouth and largemouth bass, actually my biggest largmouth about 8 lbs. and my largest smallmouth about 4 lbs came from the area that is now the putah creek nature area i think the sighn says. Its was great fishin from a float tube back then. I assume the bass are still there. Always did best in the higher flows of spring and summer, of course the warmer water of that time of year helps, never ever did good when the flows were low, theres also alot of panfish and huge carp in that area. Seems theres alot more pvt property now but the area around winters still has access, actually i beleive that if you put in at some public access you can float thourgh any privately owned areas because the property owners do not own the creek up to the high water level, but i could be wrong.