Understanding Denver Streets' decimal system; Or why the intersection of Broadway and Ellsworth is so important

Whether you've just moved to the Mile-High City or you've lived here your whole life, decoding Denver's street can be a real challenge. But the mystery of how the Denver street grid is laid out can be somewhat easily solved once you understand the importance of the intersection of Broadway and Ellsworth to the streets off the downtown grid. 

While there are plenty of resources for helping decode Denver streets, we've found that local historian Phil Goodstein's encyclopedic work, Denver Streets: Names, Numbers and Logic (New Social Publication, 1994) provides the most succinct descriptions and was the main source for this blog.

To better understand why Broadway and Ellsworth is the nexus of Denver streets, you have to go back the late 1880's when Denver street names and naming conventions were something of a free-for-all. Street names were frequently assigned by land developers and little heed was given to the difference between streets and avenues. Though some attempts were taken to govern this mess, Goodstein points out that there was generally, "no correlation between an address and the location of the street."

In 1887, the city introduced a system that allowed for addresses to consistently identify their distance from a central nexus, which turned out to be Broadway and Ellsworth. But why that intersection? To answer that question, you have to go back to 1886 when Denver had only seventeen numbered avenues which began at Seventeenth Avenue and counted down to First Avenue. "The road one block south of First Avenue, Ellsworth Avenue, was consequently defined as being the zero axis dividing the north-numbered from south numbered streets," Goodstein says.

The decimal system of 1887 codified a system in which Broadway is the dividing line between east and west avenues; and Ellsworth is the dividing line between north and south streets. There is one catch that Denver travelers should be aware of: streets that aren't specifically labeled "South" are always north of Ellsworth while avenues without the specification "west" are east of Broadway. 

For the downtown grid, which is diagonal mostly because it was laid out to follow the Platte River, a different decimal system is used. This one counts from the north using Broadway and Colfax as its nexus. 

Each block was also assigned a number based on its proximity to the nexus. For example, Goodstein points out that Federal Boulevard is 30 blocks west of Broadway hence it is the 3000 west block. 

But decimals weren't the only thing that came out of the 1887 re-ordering. City planners also introduced some order into how buildings in Denver were numbered. Since 1887, buildings on the east or south side of the street must have an even number. Buildings on the north or west side of the street must have an odd number. Though the origins of this system were rooted in Denver's earliest days, they weren't written into law until 1887. 

Various other efforts to impose order on to Denver's unruly street grid, including the fabled Mahoney System, have been undertaken over the years with varying degrees of success. Every plan had to overcome major hurdles, such as the fact that "Denver" is something of a moving target that's composed of multiple, annexed municipalities that never considered they would one day be part of the Mile-High City. But with a basic knowledge of the decimal system, and an understanding of the importance of Broadway and Ellsworth, understanding Denver's Streets gets a whole lot easier.