A Niwot resident's phone runs on Straight Talk Wireless, which uses Verizon's network, and she told 9NEWS that it hasn't worked properly since mid-May. "My biggest problem is I have no data," she said. A lot of the time her calls sit on "dialing" without making a sound, or the screen just says "emergency calls only."
Neighbors have heard a few different explanations. A resident just outside Niwot spent about 90 minutes on the phone with T-Mobile and was told the nearest tower had vandalism damage and overheating wiring. Another resident was told by a store technician that the FCC had redirected satellite signals toward Boulder. The Left Hand Valley Courier reported both accounts but did not verify either one.
The explanation T-Mobile gave in writing is different. The company said it "made network adjustments in the area" to comply with federal rules for wireless networks near the Table Mountain Radio Quiet Zone outside Boulder, and that those adjustments "have affected service in portions of Boulder County and the surrounding area." That makes the weaker signal deliberate. It's what a compliant network looks like near Niwot right now, and that changes what a "fix" can mean.
The antennas south of Nelson Road
You've probably driven past it. The Daily Camera describes the Table Mountain Field Site as "those big antennas south of Nelson Road and west of Longmont." The Department of Commerce owns the land, and the Institute for Telecommunication Sciences manages it. ITS is the research and engineering lab of the National Telecommunications and Information Administration. The site covers about 680 hectares, sits about 15 kilometers north of the Commerce campus in Boulder, and has been used for research since 1954. ITS, NIST, NOAA, the U.S. Geological Survey and partner groups all run work there.
The research is the reason the signal limits exist. ITS lists propagation studies, millimeter-wave and 5G emissions work, radar coexistence, satellite research and spectrum monitoring. In 2023 the site hosted C-band 5G base stations for a study on whether 5G could interfere with aircraft radar altimeters. Instruments that measure faint signals need the surrounding airwaves to stay quiet. When nearby towers are broadcasting at full strength, those instruments can't do their job.
The rule is decades old. The measurement is recent.
The protection comes from federal regulation 47 CFR § 1.924. It names the Table Mountain Radio Receiving Zone as a Commerce research facility and caps how strong a received signal can be at the site. The limit is 30 mV/m between 470 and 890 MHz and 1 mV/m at 890 MHz and above. The Daily Camera traced federal protections for the site back to at least 1978.
What changed is that someone measured. NTIA spokesperson Stephen Yusko told the Daily Camera that ITS found in 2024 that mobile carriers were going over the federal signal limits for the area. NTIA's statement to 9NEWS named all three national networks, AT&T, Verizon and T-Mobile, and described what came next:
"Since January 2025, ITS has worked with the operators to bring their operations back into compliance. Any resulting impacts on wireless service will need to be addressed in coordination with the network operators, who are best positioned to identify practical solutions."
Putting the reported dates in order shows why some people noticed trouble months before the complaints spread:
- 1954: Research begins at Table Mountain.
- 2024: ITS finds carrier signals above the limits.
- January 2025: ITS starts working with carriers to bring their signals into compliance.
- Mid-May: A Niwot resident's service on the Verizon network starts failing in Niwot.
- Early September: Complaints pile up on Nextdoor and in the Nifty Niwot Facebook group, mostly from T-Mobile and Xfinity customers. More than 100 FCC complaints come in from Longmont and Niwot.
A carrier-by-carrier rollout over many months fits that pattern better than a single broken tower does.
Why "fixed" means something different here
On September 30, the Courier ran a photo of a cell tower on Niwot's east edge, off 95th Street between Niwot Road and CO Highway 52. The tower is still there. Where carriers have lowered their output, though, turning it back up would put them over the limit again.
Each carrier has described its position in its own words:
| Carrier | What it said publicly |
|---|---|
| T-Mobile | "We have now achieved the required federal thresholds." Longer-term work "will be an iterative process that will require coordination with the federal government before changes can be completed." |
| AT&T | The Radio Quiet Zone requirements "apply to all wireless carriers operating in the area." |
| Verizon | "We will work to remain compliant with FCC requirements while optimizing our network for customers in and around this area." |
T-Mobile meeting the threshold doesn't mean service is back. It means the company now complies, and as of the October 5 reporting, compliance and coverage hadn't caught up with each other. The Daily Camera put it plainly: "It's not clear, though, what the carriers can do to bring back the coverage Longmont and other Boulder County residents had come to expect." Yusko said any fixes are up to the carriers.
The rule itself leaves room for new engineering. The regulation recommends that carriers consult ITS before building, with consultation tiers based on distance and power that reach as far as 80 kilometers for very high-power transmitters pointed at the site. ITS runs field-strength analyses for proposed transmitters and can issue a Letter of Successful Coordination. Some coverage has described the zone as limiting radio signals within 50 miles. A more accurate description is a limit measured at the site itself, plus a review process for new equipment. So the realistic path back to good coverage runs through redesigned sites and antennas that land under the cap, each one checked against Table Mountain. That kind of work happens over many steps, not overnight.
Longmont City Councilmember Jake Marsing said he is willing to help carriers get the permits or infrastructure coordination they need. "People should be able to call their kids, their doctor and call 911 anywhere in this city," he wrote.
Where people say it's showing up
The reports go well beyond downtown Niwot. A Longmont Reddit post that the Daily Camera embedded listed weak T-Mobile speeds along Clover Basin, in the Sprouts parking lot, throughout Clover Creek and along Niwot Road at 95th Street. A delivery driver in west Longmont said he sometimes can't mark orders as delivered in southwest Longmont. "I've not been able to work in that part of town," he said. A T-Mobile customer described "a complete dead zone within like at least a five-mile radius of southwest Longmont."
These are individual accounts, not a coverage map. Still, they cluster in the part of eastern Boulder County between Niwot and the site. One resident commenting on Nextdoor said the problem had gone "from being a nuisance situation to an emergency."
What to set up while the engineering catches up
No local agency has issued guidance specific to these outages. The standing emergency rules in Boulder County and Longmont already cover the gaps a weak signal creates, though, and most of these steps take a few minutes:
- Sign up for BOCO Alert. Text and voice alerts are opt-in, and so are email alerts. Lumen landlines and Xfinity VoIP lines get voice alerts automatically. Other numbers have to be added to a BOCO Alert account.
- Check that Wireless Emergency Alerts are on in your phone settings. Boulder County says WEA is automatic as long as it's enabled.
- Turn on Wi-Fi calling and confirm your registered address. A 2021 FCC report said Wi-Fi calling can help where cell coverage is weak. It also warned that the feature usually doesn't send an automatic location, so a 911 call depends on the address you registered, and a call placed somewhere else may be routed to the wrong place. Several residents told the Courier that FaceTime Audio and WhatsApp worked over Wi-Fi even when Wi-Fi calling didn't.
- Know the Text-to-911 rules. Longmont advises calling whenever you can and texting only when a voice call isn't possible. Start your text with your exact location, because dispatchers don't receive it automatically.
- Get on the record. A resident suggested calling 611 and asking for tech support so you can be added to the existing outage ticket. The FCC complaint center charges nothing to file. When the FCC serves a complaint on a provider, the provider has 30 days to respond in writing.
- Before buying a signal booster, know that federal rules require you to get your carrier's consent and register the booster with them before you use it. The carrier can withdraw that consent.
Longmont Mayor Susie Hidalgo-Fahring was expected to bring up the cell service problem at the Longmont City Council meeting on Tuesday, October 6. As of the most recent reporting, no carrier had said when coverage near Table Mountain would improve.
At Jane Kraemer, I follow local issues like this one that shape everyday life in Niwot and Longmont. If you're planning a move and want to know how the Table Mountain changes affect a specific street, or what to ask about connectivity before you write an offer, schedule your free market consultation and we'll go through it together.
This article is general information, not legal, tax or financial advice. Consult a qualified professional about your situation.
