Is it known how closely Lt. Williams follow the religion of his mother?

One minor point–unless Williams pere lived an extraordinarily long life, Arches had not yet become a national park by the time he died. It was first established as a “National Monument” in April 1929–which can be done by presidential proclamation without specific authorization by Congress (see, for example, all the Sturm und Drang that accompanied the establishment by Pres. Clinton of Grand Staircase-Escalante National Monument). It wasn’t until 1971 that Arches became a National Park.

Which simply means that Williams’s efforts finally bore fruit in having Arches become a national park–it just took a while and a bit of a detour to get there.