Amkelley, yes, I'm in SD and my younger son and his family live a couple of miles inland where the marine influence starts to fade away. Their house is on the rim of a local canyon/valley about 6-1/2 miles long that has some great trails through it. I usually run there with him on Saturday mornings. There was no hiding from the sun and heat yesterday.
Sorry to see your problem with the hip area muscle spasms. I experienced the same problem to a lesser degree a couple of months ago when I had some sciatica problems caused by my non-running activities (gardening and construction). I just had a couple of days where, after some serious back soreness, I tried to get out and run easily, and about a half mile into my run I suddenly had spasms in my hip/quad muscles that forced me to stop. The spasms relaxed as soon as I stopped and I could walk slowly home. A couple of days rest and starting some exercises to relive sciatica problems have solved the problem for me, but now I know that I have to treat my spinal column more gently and I have significantly reduced all activities that require bending at the waist or putting stress on the back in other than the vertical direction. I would bet that your problem involves nerves being pinched in your lower back by bulging discs. I hope it settles down and you can get back to normal, but all our skeletal and connective tissue systems get less robust and resilient with each passing year, and we have to recognize that and adapt to it.