And of course if Denver was only chosen as an overnight stop option, you could go right through there next day and get closer to Arches NP. Oakley KS has limited lodging choices and is 600 miles from St Louis and the following day 550 miles would get you to Fruita CO which is just 100 miles from Arches NP. It'll be safer, more relaxed and you will arrive to Arches fresh and ready for a day of exploring.