Route guide

Lake San Marcos to Denver (CLD-DEN): Nonstop Upgrade & Award Space

United Airlines flies nonstop between Lake San Marcos (CLD) and Denver (DEN), roughly 14 times a week. With United Airlines operating this route so often, premium seats still turn over daily, and upgrade or award space can open and close within hours. 2LNR tracks confirmed availability on every CLD to DEN departure, so you know which flights have space before you book.

Data current as of July 21, 2026, refreshed on an ongoing basis as new schedules and seats are confirmed.

See CLD to DEN on the interactive map Get started free
14
Nonstop flights a week
839 mi
Nonstop distance
Free
To get started

Confirmed upgrade & award space on every CLD to DEN departure

2LNR tracks confirmed upgrade and award availability on American, Delta, and Alaska and across 30 airlines, segment by segment, date by date. Open the calendar for Lake San Marcos to Denver to see which departures have real space, or watch the route and get alerted when space opens.

See real availability

Confirmed upgrade and award seats on each CLD to DEN departure, checked against live inventory so you know what is open before you book.

Set an alert

Premium inventory turns over fast. Watch this route and 2LNR notifies you when space appears on a date you are tracking.

Plan on the map

See CLD to DEN on the interactive route map, with schedules, connections, and route statistics.

Airlines flying Lake San Marcos to Denver nonstop

Carriers operating CLD to DEN nonstop in the current schedule. 2LNR tracks confirmed upgrade and award space on each of them.

  • United Airlines
See CLD to DEN on the interactive map →

Frequently asked questions about CLD to DEN

How far is Denver from Lake San Marcos?
CLD to DEN covers about 839 miles nonstop. Flight times vary by aircraft and season; each scheduled departure on this page lists its own times.
Which airlines fly nonstop from CLD to DEN?
United Airlines is currently the only airline flying CLD to DEN nonstop. 2LNR tracks confirmed upgrade and award space on every United Airlines departure.
How many flights a week are there from CLD to DEN?
About 14 nonstop flights a week run between Lake San Marcos and Denver in the current schedule, operated by United Airlines. Frequency shifts by season; the calendar on this page reflects what's currently scheduled.
How do I check upgrade or award availability on CLD to DEN?
Open the CLD to DEN calendar on this page to see confirmed upgrade and award space by date. You can also set an alert on the Lake San Marcos to Denver route, and 2LNR will notify you when space opens. It's free to start.

Never miss CLD to DEN upgrade or award space

Track confirmed availability, set alerts, and book with confidence. Free to start, no credit card required.

Get started free