There is transportation from Denver International Airport (DIA) to the Best Western Plus in Longmont, Colorado, through Eight Black Cars https://eightblackcars.com/airport-transfers/ , 720-316-6822. Shuttle service leaves the Best Western Plus every two hours for DIA. The cost is $45.00 each way.
Green Ride Colorado (http://www.greenrideco.com/, 970-226-5533) also offers shuttle service from DIA to Longmont hotels.
The Regional Transportation District (RTD) bus to the airport (SkyRide) goes to downtown Boulder. The cost is $9.00 each way. The Bolt bus runs from the Boulder downtown terminal to Hover & the Diagonal (a block or two from the hotel).