When did the institution located in Lewiston, Maine join the conference? 
CREATE TABLE table_261931_2 (joined VARCHAR, location VARCHAR)
SELECT joined FROM table_261931_2 WHERE location = "Lewiston, Maine"
### Context: CREATE TABLE table_261931_2 (joined VARCHAR, location VARCHAR) ### Question: When did the institution located in Lewiston, Maine join the conference?  ### Answer: SELECT joined FROM table_261931_2 WHERE location = "Lewiston, Maine"