This paper deals with the problem of road network building to access forest resources. In the literature, this problem is known as the multiple target access problem (MTAP). It can be formalized as follows: given a set of targets (the trees to harvest), a source (an existing forest road) and a cost surface (the road building cost), what is the cheapest network that connects all targets to the source? We propose two heuristic methods to solve big-sized MTAPs and we compare them to existing literature methods. Heuristics are compared on the basis of (i) the cost of the network that connects the targets to the source and (ii) of the computation time required by each heuristic. Results are obtained on a theorical example from the Maunga Whau volcano (Auckland volcanic field, New Zealand) and from a Monte Carlo experimental plan using randomly generated MTAP.