Several times though the day the pack stopped to regroup or allow vehicles to cross a challenging spot on the trail.  This gave folks a chance to get out, stretch a little and take a few pictures and gather to watch the action.  In this case it was rocks and boulders that stopped the group.  After we drive through the rock garden we regrouped and proceeded though a relatively flat area.  As almost always the case in flat areas you'll find standing water that you almost inevitably have to go through (or over).