Fold3.com for the muster cards and prison records. Ancestry.com for family info.
Missouri SOS files have good info as well. Philip Odell is listed in the database.
It can be used for free here: https://s1.sos.mo.gov/Records/Archives/ArchivesDb/soldiers/Default.aspx#soldierSearch

Another good source of info for non-combatants is the Provost Marshall files here: https://www.sos.mo.gov/archives/provost/provostPDF#cat2

They are digitized copies of microfilm files so it's old school hunt and scan research but there is a lot of good info. The Civil war page of the SOS archives have a large amount of Civil War info not available elsewhere.

I took the time to search the Provost Marshall files while watching football this afternoon >:) . I find a transcript of his trial that is much easier to read than what was on Fold3. It is on Reel F1688, File# 20488.
In the specification of charge one it says he signed his oath at REEVES Station not Reavis Station as transcribed on his muster card from Gratiot. REEVES makes much more I think. You can see it for yourself here https://www.sos.mo.gov/cmsimages/Archives/Provost/f01655.pdf
You will need to scroll down in the image roll a bit to get to file 20488 but its good reading. In the second charge of being a guerrilla he was acquitted. I suspect the second charged stemmed from Leeper's input alluded to previously.

Reeve's Station is described here on the message board:
http://www.history-sites.com/cgi-bin/bbs62x/mocwmb/arch_config.pl?md=read;id=6213

Glad to help with your journey. JJR