In Ponca City, Oklahoma, on Kelley Ave above the Arkansas River.

https://maps.google.com/maps?saddr=Tulsa,+OK&daddr=Salt+Plains+National+Wildlife+Refuge,+Jet,+OK&hl=en&ll=36.694094,-97.050347&spn=0.028183,0.060511&sll=36.587966,-97.992554&sspn=0.903079,1.93634&geocode=FX6qJwIdOURH-imPLtHduJK2hzH3atkbyBBp5w%3BFYJNMQIdbPEl-iHxRI4m-T6k0Cm14aT5qpavhzHxRI4m-T6k0A&oq=salt+p&t=h&mra=ls&z=15&layer=c&cbll=36.69404,-97.050356&panoid=Zgirim4rTjcEobITMUXaPQ&cbp=12,187.61,,0,1.78