From frost to flowers

9 April:  We woke up to frost on the grass in the middle of West Virginia, but as we drove on into eastern Kentucky that same day, the temperature soared into the mid-to-high 70s.  Prominent in the scenery we drove through were redbud trees in bloom, providing colorful purplish-pink accents against the still bare hardwoods.  We camped at a very attractive campground in the Daniel Boone National Forest and went for a hike on a trail along the top of Koomer Ridge, with spring wildflowers blooming, steep drop-offs to either side of the ridge, limestone boulders, cliffs, and an arch.10 April:  Continuing west, we descended into less hilly terrain and stopped at the Abraham Lincoln Birthplace National Historic Park, which included both his boyhood home at Knob Creek Farm and his birthplace at Sinking Spring.  The informational signs and a nice long talk with a volunteer ranger made this a very worthwhile place to visit.  We continued on to Mammoth Cave National Park, and spent some time going through the visitor center displays.  Mammoth Cave is the longest in the world, with a little over 400 miles of passageways  explored and mapped so far.  During both the Revolution and the War of 1812, this cave and others in the region were valuable sources of nitrate, which was used to make saltpeter for manufacturing gunpowder.