In the prosthetic industry a trans-tibial prosthetic leg is often referred to as a BK or below the knee prosthesis while the trans-femoral prosthetic leg is often referred to as an AK or above the knee prosthesis.
The City of Black Hawk is located 25 miles West of Denver. Through Historic Central City. 1  from Denver take Interstate 70 West. 2  I-70 exit 243 to Central City/Hidden Valley.
When the SR-71 was retired in 1990, one Blackbird was flown from its birthplace at United States Air Force Plant 42 in Palmdale, California, to go on exhibit at what is now the Smithsonian Institution's Steven F. Udvar-Hazy Center in Chantilly, Virginia.