We stopped for the night at Lewis Park en route from Utah to Nebraska, and we're very happy that we did. It's barely a mile off I-25 in Wheatland.
This town park campground includes six gravel pad 20/30/50A electric sites for RVs and numerous sites for tents only. Potable water is available at several hydrants, including one right adjacent to the first site, where we stayed. There's also an RV dump available, and best of all it's all free! (But donations at the park's iron ranger are encouraged.) Maximum stay is 3 nights. Sites are reasonably level side to side, but far less so front to back.
The park itself is in immaculate condition with well-manicured grass. The town itself is neat, tidy and clean. Cell signal was solid on Verizon 4G LTE, but throughput rates were spotty.
As the other reviewer said, there are a few Union Pacific freight trains that pass right by the campground per day, but we didn't find that to be as bothersome as we expected even though we deducted one star for that "feature." The park also includes wonderful amenities for kids, including a playground, disc golf course, and one of the most elaborate and well-kept mini-golf courses that we've ever seen. There's also a municipal swimming pool immediately adjacent. But the campground is well separated from all the other activity, and we enjoyed a quiet stay before getting back on the road in the morning.
Regrettably, as we were in and out for a quick overnight we didn't snap any photos.