There is no shore nor lake involved in this trail at all. Lake Bonneville is a prehistoric lake that covered almost all of Utah that is long gone now, but left a noticeable shoreline mark following the base of the mountains. This is a very simple and easy trail leading from first dam to green canyon along that shoreline.
Park at First Dam and head into the tunnel leading underneath the highway. Its gets steep as it the trail turn from pavement to dirt, and heads along the mountains. The beginning here is the only real climb that you'll see. The scenery is beautiful looking over the valley from the shoreline.
There are two options for you to take. There is a wide gravel path that stretches the entirety of the way, or a hidden singletrack that starts part way on the trail if coming from First Dam. Look for the singletrack on the east side (toward the Mountains) for a more exciting path, or stick to the gravel for a more family friendly ride.
Trail description and GPS provided by sunrisecyclery.net