Quick family-friendly hike in Mammoth Lakes, CA.
Emerald lake is a relatively short 1.7 mile out-and-back hike. There is ample parking at the parking lot and trailhead. There is also overflow parking at the upper lot for Duck Lake and Skelton Lake.
The trail has a decent amount of uphill, but you should arrive shortly (<30 mins) at your destination depending on your group and how fast you're moving. The initial ascent is mostly switchbacks before it's starts to taper off a bit as you get closer to the lake. Once at the lake, you'll see a small beach where you can fish from. There are also rocks on the side of the lake that you can climb to get around to the other side, which adds another spot to fish from.
To get back to your car, simply head back the way you came. If you want to continue your hike, you can keep going up on the trail and look for the sign to cross over to Skelton Lake. If you head this route, your round-trip hike will be ~4.5 miles.
