The Mesa County Clerk of the Court is your most reliable source for accurate sentencing information, and it is the same place attorneys go when they need the official record on a case.
The clerk's office maintains all court documents including the judgment and commitment order, which is the document signed by the judge at sentencing that specifies the exact sentence imposed. That document tells you the length of the sentence, any conditions attached to it, and how the time is structured. It is public record and you can request it by providing your brother's full legal name and case number if you have it.
You can reach the Mesa County Combined Courts in Grand Junction by phone or in person. Many Colorado court records are also accessible online through the Colorado Courts E-Filing system at courts.state.co.us, where you can search by name and pull up case information including sentencing details without making a trip to the courthouse.
If your brother is being held at Mesa County Jail pretrial and has not yet been sentenced, the clerk's office can tell you the charges filed and any upcoming court dates. If sentencing has already occurred, the judgment order will be on file there.
For additional information about his current custody status and projected release date once he enters the state system, the Colorado Department of Corrections offender search at doc.state.co.us is worth checking as well. That database reflects where state inmates are housed and their sentence information once they have been committed to CDOC custody.
Start with the Mesa County Clerk. That is where the authoritative paperwork lives.