Participation in Colorado's delegate selection process is open to registered Democrats.

Tuesday 1 March 2016 (presumably): Colorado Precinct Caucus. Delegate Pledging: Proportional Caucus/Convention. Voter Eligibility: Closed Caucus/Convention.

Precinct Caucus
Source: Colorado Democratic Party.
Status: Unofficial. Retrieved: Sunday 13 March 2016.
Included in Nationwide vote.

There are two separate processes in Colorado that are dealt with simultaneously: Caucuses and conventions select Colorado's National Delegates while assemblies designate candidates for nomination at the August Colorado state primary.

Tuesday 1 March 2016 (presumably): First tier Caucuses meet in each precinct to choose delegates to the next tiers in proportion to the percentage of the support each candidate receives at said caucuses- a mandatory 15 percent threshold being required for such allocation. How the Democratic Proportional Delegate Allocation Math works.

A fine point: In some counties delegates are elected from the precinct caucuses to the congressional and/or state assembly/conventions. In other counties, delegates are elected from the precinct caucuses to the county assembly/conventions and then to the congressional assembly/convention and state assembly/conventions.

14 April 2016: Colorado Democrats admit mistake that cost Bernie Sanders key delegate from The Denver Post. " The new projection ... shows [Sanders] winning 39 delegates ... compared to 27 for Clinton." We are now showing this split on the top of the page.
 
The party has added the message "These are unofficial results from March 1st only and should not be used in any way to determine the allocation of delegates or the estimation of delegates to be awarded to the Democratic National Convention." to the link to their results below.
 
We will update the table below when the party posts the corrected data.

National Convention Delegate Estimate
Based on the Precinct Caucuses
Source: Colorado Democrats - 2016 Caucus Results.
Status: Unofficial. Retrieved: Sunday 13 March 2016.

NOTE: It is the Congressional District and the State Conventions [with delegates to both chosen by the aforementioned County Conventions] that will, respectively, actually pledge Democratic National Convention delegates to presidential contenders.

Wednesday 2 March - Saturday 26 March 2016 (presumably): County Assemblies/Conventions - held no later than 25 days after (no later than 26 March 2016) precinct caucuses.

Delegates to the Congressional District and State Conventions are allocated to presidential contenders in proportion to the percentage of the support each candidate receives at the County Conventions- a mandatory 15 percent threshold being required for such allocation.

NOTE: It is the Congressional District and the State Conventions [with delegates to both chosen by the aforementioned County Conventions] that will, respectively, actually pledge Democratic National Convention delegates to presidential contenders.

Friday 1 April - Friday 15 April 2016 (presumably): Congressional District Assemblies/Conventions. Delegate Pledging: Proportional Caucus/Convention. Voter Eligibility: Closed Caucus/Convention. 43 of 78 delegates to the Democratic National Convention are pledged to presidential contenders based on the results of the voting in Colorado District Conventions. A mandatory 15 percent threshold is required in order for a presidential contender to be allocated National Convention delegates at the congressional district level.

• 43 district delegates are to be allocated proportionally to presidential contenders based on the convention results in each of the State's 7 congressional districts.

Source: CD & State Conventions / Assemblies.

District Conventions

National Convention District Delegates are elected at the district conventions.

CD 1: 9 April. National Convention District Delegates elected-- Clinton: Robert Rodriguez, Hon. Wellington Webb, Hon. Elbra Wedgeworth; Sanders: Cleo Dioletis, Jeremy Gall, Mark Lasser, Nita Lynch, Kona Morris.
CD 2: 2 April. National Convention District Delegates elected-- Clinton: Hon. Dickey Lee Hullinghorst, Sonya Jaquez Lewis, Braulio Rojas; Sanders: Giselle Herzfeld, David Levy, Sarah Moore, Andrew Romano.
CD 3: 15 April. National Convention District Delegates elected-- Clinton: Mary Beth Corsentino, Sal Pace; Sanders: Erin Biggs, Pamela Liu, Root Routledge, Joseph Thomas.
CD 4: 15 April. National Convention District Delegates elected-- Clinton: Kathleen Ensz, Jared Sutton; Sanders: Matthew Brown, Lynnette McClain, Jason Sherry.
CD 5: 15 April. National Convention District Delegates elected-- Clinton: Judith Ingelido, Michael Perez; Sanders: Angelina Hagan, Jene Hanna, Michael Maday.
CD 6: 10 April. National Convention District Delegates elected-- Clinton: Amy Drayer, Patricia Shaver, Bryan Hartmann; Sanders: Christopher Davis, Thomas Grushka, Allison Vail.
CD 7: 9 April. National Convention District Delegates elected-- Clinton: Evie Hudak, Odell Barry; Sanders: Gabriel McArthur, Emilie Mitcham, Euell Santistevan, Terry Tucker.

Saturday 16 April 2016 (presumably): State Assembly/Convention convenes in Loveland, Colorado. Delegate Pledging: Proportional Caucus/Convention. Voter Eligibility: Closed Caucus/Convention. 23 of 78 delegates to the Democratic National Convention are pledged to presidential contenders based on the preferences of convention participants as a whole. A mandatory 15 percent threshold is required in order for a presidential contender to be allocated National Convention delegates at the statewide level.

• 14 at-large National Convention delegates
• 9 Pledged PLEOs

These statewide delegates are elected by the State Convention.

Bernie Sanders wins Colorado with big showing at state convention from The Denver Post. "The Vermont senator takes 41 of the state's 78 DNC delegates, as Hillary Clinton claims 25."

State Convention
Source: The Denver Post.
Status: Unofficial. Retrieved: Saturday 16 April 2016.

16 April. National Convention District Delegates elected-- PLEO: Clinton: Rep. Crisanta Duran, Mayor Michael Hancock, Sheila Lieder; Sanders: Joann Fujioka, JoyAnn Keener-Ruscha, Raffi Mercuri, Rep. Joe Salazar, Jeri Shepherd, Rep. Jonathan Singer.
At-Large: Clinton: Hon. Polly Baca, Josie Heath, Sen. Rollie Heath, Harold Jobson, Hon. Sue Schafer; Sanders: Victoria Bard, Cortland Coffey, Jessica Crowe, Spencer Duncan, Wendy Howell, Michael McCorkle, Kimberly Netherton, S. Smith, Luis Franisco Vaszuez.

The remaining 12 National Convention delegates consist of

• 12 Unpledged PLEO delegates:
• 6 Democratic National Committee members.
• 4 Members of Congress (1 Senator and 3 Representatives).
• 1 Governor.
• 1 Distinguished Party Leader (former DNC Chairman Roy Romer).

These 12 delegates and will go to the Democratic National Convention officially "Unpledged".

SB 15-287, introduced on 29 April 2015, would establish a Presidential primary on a date selected by the Governor. The date must not be earlier than the major political parties allow without penalty and not later than the 3rd Tuesday in March. This bill died in committee circa 5 May 2015.