It so happens that the Census released Colorado data
today. You can find it
HERE.
And you're right!
Here are counties >100,000
Code:
1. El Paso 622,263
2. Denver 600,158
3. Araphahoe 572,003
4. Jefferson 534,543
5. Adams 441,603
6. Larimer 299,630
7. Boulder 294,567
8. Douglas 285,465
9. Weld 252,825
10. Pueblo 159,063
11. Mesa 146,723
And cities >100,000.
Code:
1. Denver 600,158
2. Colo Sprgs 416,427
3. Aurora 325,078
4. Fort Collins 143,986
5. Lakewood 142,980
6. Thronton 118,772
7. Pueblo 106,595
8. Arvada 106,433
9. Westminster 106,114
10. Centennial 100,337
Fort Collins passes Lakewood for #4.
Pueblo passes Arvada, but stays at #7 because Thornton jumps way up.
Boulder drops out of the top 10 completely, and is finding itself within strinking range by Longmont. By the next census, Boulder may well no longer be the biggest city in Boulder County.