I've discovered the HGRA web site doesn't have directions to Riverside One field.
5 – Riverside 1 – (Lexington and W. 7th, by the school bulding.)
You can see it on Google maps.
When I go south down Lexington, I turn left on Albion Ave (just before Lex meets 7th) then look to park. I think there's school parking we can use.
There are two fields seen in the sat map, I don't know which we use. The north one looks bigger.