Question: What is the name of the commercial airline that serves this public use airport (owned by the city and county) near the city in Valley County, Montana with a population of about 3,400 as of 2015?

Context paragraphs:
Brookings Regional Airport: Brookings Regional Airport (IATA: BKX, ICAO: KBKX, FAA LID: BKX) , formerly known as Brookings Municipal Airport, is a city owned, public use airport located in Brookings, a city in Brookings County, South Dakota, United States.  It is included in the National Plan of Integrated Airport Systems for 2011–2015, which categorized it as a "general aviation" airport.  Starting from September 2009, the airport is no longer served by a commercial airline after the United States Department of Transportation ended the subsidy for this airport's Essential Air Service program.

Meridian Regional Airport: Meridian Regional Airport (IATA: MEI, ICAO: KMEI, FAA LID: MEI) is a public use airport located at Key Field, a joint use public/military airfield.  It is located 3 NM southwest of Meridian, a city in Lauderdale County, Mississippi, United States.  The airport is owned by the Meridian Airport Authority.  At 10003 ft , Key Field is home to the longest public use runway in Mississippi.  It is mostly used for general aviation and military traffic, but is also served by one commercial airline with scheduled passenger service subsidized by the Essential Air Service program.

L. M. Clayton Airport: L. M. Clayton Airport (IATA: OLF, ICAO: KOLF, FAA LID: OLF) is a public use airport located three nautical miles (6 km) northeast of the central business district of Wolf Point, a city in Roosevelt County, Montana, United States.  It is owned by the city and county.  The airport is served by one commercial airline, subsidized by the Essential Air Service program.  Reportedly, this made it the smallest airport in the 48 contiguous states with regularly scheduled air service.

Glasgow Airport (Montana): Glasgow International Airport (also known as Wokal Field, IATA: GGW, ICAO: KGGW, FAA LID: GGW ) is a public use airport located one nautical mile (2 km) northeast of the central business district of Glasgow, a city in Valley County, Montana, United States.  The airport is owned by the city and county.  It is served by one commercial airline, subsidized by the Essential Air Service program.

St. Cloud Regional Airport: St. Cloud Regional Airport (IATA: STC, ICAO: KSTC, FAA LID: STC) is a city owned, public use airport in Sherburne County, Minnesota, United States.  It is located four nautical miles (5 mi, 7 km) east of the central business district of the city of St. Cloud, which owns and operates the airport.  The airport serves private, commercial, corporate, cargo and military operations.  Mostly used for general aviation, it is also served by one commercial airline.

Havre City–County Airport: Havre City–County Airport (IATA: HVR, ICAO: KHVR, FAA LID: HVR) is a public use airport located three nautical miles (6 km) west of the central business district of Havre, a city in Hill County, Montana, United States.  It is owned by the City of Havre and Hill County.  The airport is served by one commercial airline, subsidized by the Essential Air Service program.

Barnwell Regional Airport: Barnwell Regional Airport (IATA: BNL, ICAO: KBNL, FAA LID: BNL) is a county owned, public use airport located one nautical mile (2 km) northwest of the central business district of Barnwell, a city in Barnwell County, South Carolina, United States.  It is owned by Barnwell County.  It is included in the National Plan of Integrated Airport Systems for 2011–2015, which categorized it as a "general aviation" facility.  The airport does not have scheduled commercial airline service.

Magic Valley Regional Airport: Magic Valley Regional Airport (IATA: TWF, ICAO: KTWF, FAA LID: TWF) , also known as Joslin Field, is a public use airport located four nautical miles (7 km) south of the central business district of Twin Falls, a city in Twin Falls County, Idaho, United States.  The airport is owned by the City and County of Twin Falls.  It is mostly used for general aviation but is also served by one commercial airline.

Glasgow, Montana: Glasgow is a city in and the county seat of Valley County, Montana, United States, with an estimated population of 3,414 as of 2015.

Lake Cumberland Regional Airport: Lake Cumberland Regional Airport (IATA: SME, ICAO: KSME, FAA LID: SME) is a public use airport located three nautical miles (6 km) south of the central business district of Somerset, a city in Pulaski County, Kentucky, United States.  The airport is owned by the city of Somerset and Pulaski County.  It also serves the area around Lake Cumberland.  It is mostly used for general aviation, and from late 2008 until February 2010, was served by one commercial airline, Locair.  The $3 million federally funded passenger terminal was converted to the FBO in September 2011.

Supporting paragraphs: Glasgow Airport (Montana) Glasgow, Montana
Answer: Essential Air