With a weather forecast of thunder storms in the middle of the day, we decided being up on a mountain was not the best idea, so changed the  hike from Tire Mountain to a section of the North Umpqua Trail.  Five  people hit the fern lined trail to Elevation Rock.  After about three  miles following the trail as it climbs gently though the woods above the river, crosses a couple of small steams and goes past a couple of waterfalls, we arrived at Elevation Rock.  Most of the spring flowers were already done blooming.  A couple of patches of twin flower and a few iris were about all we saw along the trail.  A little more searching revealed a few wild ginger blooms.  Most surprising was the Western yellow oxalis (Oxalis suksdorfi) that we saw.  We're not used to seeing yellow oxalis.  When we got to Elevation Rock, we were delighted with a patch of cats ears.  Some of us turned around at Elevation Rock as thunder clouds were gathering and we wanted to get back to the car before the storm.  That gave us a 6 mile hike.  Some of the hikers went on an extra mile for an 8 mile hike.  No one had a camera along, so no photos.