We lived in Eau Claire for 23 years. We stay at the Northern Wisconsin State Fairgrounds in Chippewa Falls when visiting Eau Claire. Just 10 minutes to Eau Claire. Not much else closer, unless you go to the Eau Claire County Expo grounds, but those sites are depressing.
If you don't need full hookups Harstad County Park is a nice spot. Eagle Ridge in Lake Hallie (Chippewa Falls address) is fairly new and is well situated for visiting Eau Claire.
2013 Leisure Travel Vans Unity U24MB, 635 watts solar, 440 AH batteries, 2000 watt inverter, Koni struts and shocks, Hellwig rear anti-swaybar, SumoSprings front and back, 2012 Hyundai Accent SE, Blue Ox baseplates, Aladdin towbar and Patriot