Checked my Cyclemeter app again today and it showed 1,170 feet of gain in the morning and 2,594 in the afternoon, for a total elevation gain of 3,764 over 30.5 miles. That would equate to 10,000+ feet of climbing extrapolated to a century ... which is why I don't believe these GPS readings. The other reason why I don't trust the readings is that vary widely from day to day, riding the same route.