Excellent question! Yes, there are several great places to SUP near Ashland. In fact, my family regularly paddleboards. At Emigrant Lake, which is located just a few miles from town, maybe people SUP from the boat dock area at the county park, or from the campground or beach. During peak season (June-August), several kiosks on-site rent paddle boards by the hour or day as well.
About 45 minutes from Ashland in the scenic Applegate Valley. It’s lovely to SUP on Applegate Lake as well. From Ashland, take I-5 to the Phoenix exit, then follow signs to Jacksonville. From there, take Highway 138 to Applegate Lake. You can also head out Highway 140 to Fish Lake or Lake of the Woods, or Highway 62 (from Medford) to Lost Creek Lake.
For the adventurous and advanced, we have also seen quite a bit of SUP activity on the Rogue River, particularly on the (mostly) calm section from Lost Creek Dam to Shady Cove (also on Highway 62, before you reach Lost Creek Lake). There are riffles and Class I-II whitewater to contend with, however.
Have fun in Southern Oregon paddleboarding!