LKV Realty
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$6,800,000
$7,200Reward *
3421 4th Street, Boulder, CO 80304Listing ID IR1053821

3421 4th Street, Boulder, CO 80304

Active
Fourth Street 3403 Sub
Time on site: 151 daysLast updated: 9 hours ago
Property Type
Property Type
Residential
Property Sub Type
Property Sub Type
Single Family Residence
Bedrooms
Bedrooms
6
Bathrooms
Bathrooms
5
Square Feet
Square Feet
5,198
Acres
Acres
0.6
Days on Site
Days on Site
152
Cooling
Cooling
Ceiling Fan(s), Evaporative Cooling
Heating
Heating
Forced Air, Hot Water, Radiant
Year Built
Year Built
1990
Garages
Garages
2
Parking
Parking
Oversized

Newlands Sanctuary on Mt. Sanitas Open Space Step onto the 600-square-foot deck and look up. Mt. Sanitas rises 1,300 feet from your backyard gate, private access to the Goat Trail. No driving. No parking. Just you, your coffee, and maybe a 4-legged friend who will make sure you don't skip it. This premier property is one of eight homes backing directly to open space. In 21 years, only one has changed hands. Hidden behind a 70-yard tree-lined driveway on a 0.6-acre lot (2.5x standard), this is widely regarded as one of Boulder's best addresses, served by top rated schools.The 5,200-square-foot residence features 20-foot ceilings with west-facing glass framing Mt. Sanitas, white oak floors, two fireplaces, and a library overlooking the property's seven heritage apple trees. Six bedrooms plus office (convertible seventh) include three distinct suites: the primary en-suite with a stunning view; a garden-level walkout in-law addition (2005, 12' ceilings) with separate entrance, private patio, and dedicated office-ideal for multigenerational living or guests-plus a basement suite with whirlpool bath. Outside you will discover a deep wrap-around porch beneath a 60-foot silver maple, flower and vegetable gardens, and the historic Silver Lake Ditch with 12,000 gallons daily water rights. Sundance Film Festival arrives January 2027, venues minutes away providing a chance at an incredible rental income opportunity and under the Augusta Rule, 14 days of rental income may be tax-free. Roof replaced 2019. New carpet. Heated two-car garage. No HOA. No covenants. For those who know Newlands: this is the privacy, the lot, the view, and the trail access that almost never comes to market. For those discovering Boulder for the first time: welcome to the neighborhood the locals covet most.

Property Information

Property Details

Location

Address
3421 4th Street
County
Boulder
City
Boulder
Zip Code
80304
Subdivision
Fourth Street 3403 Sub
School District
Boulder Valley RE 2
High School
Boulder
Elementary School
Foothill

Interior Features

Beds and Baths

Bedrooms
6
Main Level Bedrooms
1
Full Bathrooms
2
Half Bathrooms
1
3/4 Bathrooms
2

Building

Building Information

Square Feet
5,198
Year Built
1990
Construction
Frame, Wood Siding
Roof
Composition

Property Taxes

Tax Annual Amount
$26,030
Tax Year
2025
Colorado Realty 4 Less, LLC, (970) 531-7448

Market Report for 80304

* The market data shown is based on available information from Multiple Listing Service (MLS) and/or public records. Data provided is for informational and educational purposes only and may not represent the full housing market. For more accurate information, consumers should consult a certified appraiser or licensed real estate agent.

*Average of $2,150 in rewards is calculated based on the purchase or sale of a home between $400,000 to $449,000. The median home price for all housing types is in the United States is $405,400 as of 2025 as reported by the National Association of Realtors® (NAR). The actual reward amount may vary depending on the purchase or sales price of the home. Please see the Lakeview Home Rewards program terms and conditions for more details. The National Association of Realtors® is a registered trademark of the National Association of Realtors®.

Source: REColorado
REColorado logo

Based on information submitted to the MLS GRID as of 11 Aug 2026, 08:06 PM UTC. All data is obtained from various sources and may not have been verified by broker or MLS GRID. Supplied Open House Information is subject to change without notice. All information should be independently reviewed and verified for accuracy. Properties may or may not be listed by the office/agent presenting the information. Some IDX listings have been excluded from this website.

For corrections to this data please contact Brytecore MLS Support.

RECIRP00465