The picture on the Google maps link with the silver van and land rover was taken when the park is closed. (Check the Irving Nature Park site for dates and park maps) You can still park here though. This portion of the trail dips behind the barn, takes a hard right and follows an old dirt road for a wee bit then goes up to some nice single track that takes you through south facing slopes with mature, but gnarled from the coastal winds, yellow birch and other hardwoods. You will run right by the Sheldon point lookout so stop and have a view. After that you will wind through a bit of alders and then parts of a gravel pit that finally dumps you out at the beach. Run along with the eroded sand bluffs to your right to eventually get to the Saint's Rest beach proper and the causeway. This takes you to the main part of INP where you can follow the perimeter trail through mossy spruce forests, across small, intimate beaches and even some hardwood groves.
You will end up back at the causeway and so can retrace your steps from there. A Google Earth track is on the link below.