Jessica Lawson fell into a lake in the Massif Central region on 21 July 2015. She died in hospital the next day.
Her father Tony said: "We still don't know to this day exactly what happened to Jess while she was in their care."
East Riding of Yorkshire Council said it would not comment until a French inquiry into the incident ended.
Mr Lawson, from Kirk Ella, on the outskirts of Hull, said he was due to meet Education Secretary Nicky Morgan on Thursday.
Jessica was one of 24 students and three staff from Wolfreton School in Willerby that were on a five-day trip to the Club Correze adventure centre near Meymac.
It is believed she became trapped under an overturned pontoon, which she and a group of children were jumping from while swimming.
Mr Lawson said: "Twelve months on and we still have more questions than answers, both from the school and East Riding of Yorkshire Council. Their only advice to us is 'seek legal advice' and that was basically it."
He said the family had been left isolated and alone, and he did not want others to go through what they had experienced.
Speaking ahead of the first anniversary of Jessica's death, he said: "18 July is the day I put her on the bus and waved her goodbye and that's probably going to be the hardest day for me. That was the last time we saw her. We never expected for her to never return back on the coach with the other 23 children."
Kevin Hall, director of children's services at the council, said he recognised the lack of information coming from the investigation in France was "very difficult" for the family.
"Regrettably, the council is not able to influence the speed of the judicial process by the French authorities and until those investigations are complete it would be inappropriate to comment further," he said.
"However, we do not underestimate the emotional impact this must be having on all concerned."
Headteacher Dave McCready said his "thoughts go to [the] family at this sad time".
The Foreign and Commonwealth Office said it was "continuing to support the family".
The father of a 12-year-old girl who died on a school trip in France says he is still waiting for answers 12 months after her death.