your information you provided is a bit thin, but I fire off a guess. WTB makes a fairly tough gravel grinder for under $30 called the All Terrain, and it comes in a 32 size which is the largest you can use and for the circumstances you described you need the widest tire you can get. WTB also makes a better tire that cost about $25 more than the All Terrain called the Cross Boss. There is also the Panaracer GravelKing SK which also comes in a 32 that will cost you about $46. Also Panaracer makes a tire called the Ruffy Tuffy, but I think that tire is a bit narrow for idea traction on gravel but it is an option, it is also an almost smooth tire which I don't think would be real good on gravel. Another possibility is the Panaracer T-Serv Protex which cost about $48.
The smoother threaded tires can get greasy when things get wet, so understand that.
Anyway research those tires I mentioned and see which one fits your needs the best.