Nice ride Nate!
I have been lax this winter about working out (pretty much haven't). I went out a week or so ago to do an 18-22mi ride, and bonked at about 10 miles, to the point where I was wondering if I was going to make it home. Did a bit over 16, and did make it home. I knew there was no one at home or able to come rescue me, so I had to do it myself Strange that I rode 18 miles just fine in January on a rare nice day. I did another 16 mile ride last week and got tired, but not as bad as the first one. Just really out of shape I guess, and in two months.
Jim: nothing at all wrong with clips and straps. I didn't switch to clipless until last year, but could go back. I'm using eggbeaters (and occasionally a pair of Time ATACs) and will stick with mountain shoes instead of road shoes cuz you can walk in them. My normal pedals w/clips/straps would not fit tennis shoes or whatever, and I have narrow feet. I've used some Avocet M30 touring shoes for years. The biggest thing is that the soles are stiff enough. If you like sandals, the Keens should be great.