You're looking for a two-stage multi located along the blue trail. Even though the hike is under .75 miles round trip, you'll need to be reasonably fit to retrieve this cache.
According to TURTLE and jashounds, “At the intersection of Reservoir Road and Cedar, there is a sign that says “No Trespassing”. This pertains only to the reservoir. Reservoir Road is a public road and you have the right to travel on it. DO NOT fish, swim or otherwise enter the reservoir.”