Building a road to our inherited island that will become a new mine

So we inherited a cabin and an island up in the back country. After hearing that there is gold on the island we had came up to check it out and sure enough there is. We hired a drilling company to come out and check the island out and it turns out that it is loaded with gold. Taking this information to the bank we proceeded to get a loan from the bank and started out up to the area. One of the requirements from the bank stated that we had to have land access to the property so a land bridge is what we will build