Boulder Pioneers Project

This is the earliest record of taxpayers in Boulder County, Colorado and although the ledger gives the names, valuation of property, county tax, school tax, Territorial tax, number of polls owed and the total, it does not indicate where each taxpayer owned property.

https://irongate.com/books/research_books/boulder-county-taxpayers-series/boulder-county-colorado-taxpayers-1866-1867-an-index/