Hot Springs is a fair distance from the Mine, Do you plan on just making a day trip to the Diamond Mine or staying for a day or two? It has it's own campground but there are also CORP of Engineer campground nearby on Lake Greeson. Crater of Diamond State Park
Unfortunately if not boating there is not a lot to do or see on this end of Lake Greeson.
Crater of Diamonds SP should be able to handle it plus they just improved all the sites. Haven't been since the redo but was told they are nice. Hot Springs NP has a campground but do not know any info on length
Crater of Diamonds will fit you and is really great since the update. the NP in Hot springs should fit you as well.
they are both convenient for what you want to do.
Sue soos-ontheroad.blogspot.com
Fulltiming since 2009
2012 Mobile Suites 36 TKSB4 pulled by a
2011 Ford F450