Martinelli Ranch (GGNRA) is one of the California parks in thicket's catalog. thicket is a field guide to the parks near you: it maps the ones you have never noticed, gives you a reason to actually go, and keeps a record of where you have been.
Where it is
Martinelli Ranch (GGNRA) is in Marin County, California. Its approximate coordinates are 38.07705, -122.82045.
Check in at Martinelli Ranch (GGNRA)
thicket verifies you are actually here by GPS when you check in, so a visit means you went. Checking in builds a streak, earns achievements, and fills in your map of the places you have been.