RV Camp Suggtions around Burley Id. 84 hiway area?

Any suggestions for two nights stay around the junction of 84-86 in Idaho in the first week of May 2020. I guest Heyburn is the nearest City references I have. Was thinking of Castle Rocks State Park but, It is approximately 50 miles off of 84. If I can find a nice place a little closer in the area and save 100 miles trip off of 84 so be it. But if Castle Rocks State Park is the place to be and place to see we are willing to do it. Note: Headed to Heber City, Ut after that. First time on a long RV and don't know the good from the bad RV camps are. Don,t mine State and county parks either. Sometimes quite off the main road county RV sites are clean and nice, but some are like down town Portland, Oregon homeless camps. Retired now and trying to slow down at 63. I willing to give a hand up but not a hand out for the rest of ones life. If someone is physical and able mined I say; no workie no eatie, Veterans First are on my list to help out. Yes I worked in 20 minus degree weather for months on end and nothing was ever just given to me.