Looking at the online maps, the "Whitney Portal National Recreation Trail" is about 200 meters from that parking area. Here's a link to a gmap4 map of the area, showing the satellite view. If you click the "t4" map, you can see the trail marked.
http://www.mappingsupport.com/p/gmap4.php?ll=36.594954,-118.204483&z=16&t=sIf you switch back and forth between "satellite" (aka Aerial Google Satellite) mode to the "t4" (aka Topo high USA), you can see how to find the trail from the parking lot. The parking lot is the gray area above and left of the crosshairs, and the NRT is below the crosshairs.
Great link to the satellite map, Steve.
I've hiked on the "National Trails" trail and looked across to the sandy parking lot... that green strip is Lone Pine Creek, with very steep and loose banks. Also the trail is in deep shade as it goes up canyon, so conditions are icy in winter.
Hiking up the road is much easier than attempting the bushwack.
