Well, since the Earth is spherical (shaped like a ball), you can actually reach
any of them by traveling west from anywhere.
But the only US state capital whose west longitude is greater than 150° is
Honolulu HI.
There seems to be a confusion in your question. Denver is the capital of the state of Colorado, not the other way around.
15 S 47 W is Vila Boa, State of Goiás, Brazil.
Charleston WV is about 31 miles northeast of that point.
The biggest city in West Virginia is Charleston. It is the state capital and has a population of around 50,000 people.
The state capital closest to the coordinates 40 degrees north latitude and 75 degrees west longitude is Harrisburg, Pennsylvania. This location is situated just slightly to the northeast of those coordinates. Harrisburg serves as the capital of Pennsylvania and is located along the Susquehanna River.
Austin is the capital city in the U.S. state of Texas, a state that borders the Gulf of Mexico. The 100 degree west longitude line pass through Texas.
Denver, Colorado
Austin is the capital city in the U.S. state of Texas, a state that borders the Gulf of Mexico. The 100 degrees west longitude line pass through Texas.
The state capital that is east of the 90 degree west longitude line is Jackson, Mississippi. It is located in Hinds County in the northeastern part of the state.
West Virginia is the mountain state that borders only other mountain states. The capital of West Virginia is Charleston.
Austin is the capital city in the U.S. state of Texas, a state that borders the Gulf of Mexico. The 100 degree west longitude line pass through Texas.
The capital of West Virginia is Charleston.
Honolulu, Hawaii
Honolulu, Hawaii is the only state capital in the US that is west of 150 degrees W longitude.
Austin is the capital city in the U.S. state of Texas, a state that borders the Gulf of Mexico. The 100 degrees west longitude line pass through Texas.
Belgium
The capital of the only state that is bordered by one of the Great Lakes is Lansing, which is the capital of Michigan. Michigan is bordered by Lake Michigan to the west.