utility_name                    state   county                          unique_id
Alaska Village Elec Coop, Inc   AK      Borough, Kodiak Island          221AK
Wolverine Pwr Supply Coop, Inc  MI      Allegan, Antim, Barry, Benzie,  20910MI
Wolverine Pwr Supply Coop, Inc  MI      Clinton, Eaton, Emmet, Gratiot  20910MI
Wolverine Pwr Supply Coop, Inc  MI      Grand Traverse, Ingham, Ionia   20910MI
Wolverine Pwr Supply Coop, Inc  MI      Isabella, Lake, Leelanau        20910MI
Wolverine Pwr Supply Coop, Inc  MI      Manistee, Mason, Mecosta,       20910MI
Wolverine Pwr Supply Coop, Inc  MI      Missaukee, Montcalm, Muskegon   20910MI
Wolverine Pwr Supply Coop, Inc  MI      Newaygo, Oceana, Osceola            20910MI
Wolverine Pwr Supply Coop, Inc  MI      Ottawa, Alpena, Charlevoix      20910MI
Soyland Power Coop Inc          IL      McDonough, McCoupin             40307IL
Soyland Power Coop Inc          IL      Menard, Morgan,Montgomery       40307IL
Soyland Power Coop Inc          IL      Sangamon,Schuyler,Scott,Pike        40307IL

Alaska Village Elec Coop, Inc    AK Borough    221AK
Alaska Village Elec Coop, Inc    AK Kodiak Island    221AK

gen long id = _n
gen ncounties = length(county) - length(subinstr(county, ",", "", .)) + 1
expand ncounties
bysort id : gen id2 = _n
su ncounties, meanonly
gen county2 = ""
forval j = 1/`r(max)' {
     replace county2 = county`j' if id2 == `j'
}