Hi Greenriver,
Just got home from our second trip to Clermont in the past month, we go there regularly during the winter months.
2WD or 4WD is not really the issue at Clermont GPAs when it is dry and this year has it been really dry out there. The issue is ground clearance. We drive a 2WD Isuzu D-Max ute and have found some of the forests have badly constructed whoabouys in them. Whoabouys are also called whopped-de-dos by some people, they are the mounded earth structures placed across the roads to divert water off the road and into a side gutter. They stop water from flowing down the middle of the road way and thus gouging out the road surface.
Most GPAs at Clermont are within State Forests which are actively managed and harvested for timber thus the roads are kept to a fairly high standard for harvesting vehicle access. To protect the roads from torrential tropical downpours they build a lot of these whoabouys. Most are crossable by a careful slow approach. Some however are too steep and we have actually gotten stuck on top of one of them last year. About 3 hours later with much digging, jacking and rock depositing we managed to back off it again.
This winter has been exceptionally dry and last week we encountered large pockets of bulldust that were not there at the beginning of the season. That bulldust will form mud holes which you will not get through with a 2WD after significant rainfall. We had a few storms circling last week, but no rain. I think it has rained out there in the past few days since we left though.
Don't try to drive into Bathampton or McMasters if it has rained as you will get stuck. There are plenty of places you can access Bathampton, 4 Mile and Birimgan by just parking beside the bitumen on Laglan Road and walking in from there. The left hand side of McDonalds Flat is likely to be accessible after rain, but less so the right hand side.
Good luck, we find gold there each time we go, but it is often small and as Ship of Fools says you will have to walk to find it.
Cheers,
Troutman