The Overtoun Burn starts high in the Kilpatrick Hills and tumbles down, gaining power as more streams join it. Otters use this burn as their commuter route up to the Black Linn, a reservoir now disused but well-stocked with brown trout. If you’re observant you might spot a footprint or a spraint (otter poo) but you’ll have to be very lucky to see the otters themselves. Quoted from Geocaching.