The Elephant Back Trail in Yellowstone National Park is a nice, wooded hike with intermittent views to a wonderful overlook of Yellowstone Lake. The trail alternates between either being level or on the steeper side instead of a gradual grade. The trail creates a loop at the top so the trail has a bit more variety than a simple out and back.
The Elephant Back Trail is located near Lake Village. It starts out as a level walk through an airy, lodgepole pine forest. It then begins to climb for a bit, then get level for a bit, and basically alternates in large sections of either being very level or steep (as opposed to a steady grade). The trail reaches a junction of the loop that goes up to the overlook and back down.
I took the loop to the right and steeply climbed through more of the same lodgepole with limited views. Close to the top, a couple of nice views of the Yellowstone River coming out of Yellowstone Lake give you a chance to catch your breath and take a picture. The trail begins to loop back and level off, leading you to a nice overlook of the lake. The views of the lake here are really great. A couple taller trees stop it from being completely unobstructed, but those are minor quibbles with an otherwise great view of this enormous lake.
From there, the trail loops back down through some cool rock formations. This section of the loop has more pocket views of the lake, albeit limited.
One thing special nice about the Elephant Back Trail is the abundance of forest wildlife. Keep your eyes peeled for the wide variety of forest birds and mammals such as red tree squirrels and the pine marten that I was able to see. This area is also used for bears moving to and from the outlet of the lake. Bring bear spray, make noise and stay alert.