20:
122:
129:
630:
587:
505:
and slightly lower eastern ridge lines. On the neighboring ridges that formed the opposite slope of the ancient mountain, the same three rock layers are exposed in reverse order, with the oldest rocks near the hinge of the fold. Since the rock layers on these ridges are not vertical, the
Tuscarora Formation underlies a much higher crest, and the Bald Eagle Formation creates a series of lower "terraces" broken by small ravines.
586:
37:
459:
504:
The
Tuscarora Quartzite is more resistant to erosion than Bald Eagle sandstone, and both are more durable than the Juniata Shale sandwiched in between. Softer rock layers on either side of these eroded, leaving the double crested Bald Eagle Mountain ridge, with a depression between the higher western
579:
excavated from this formation. The planned I-99/I-80 interchange further north in the
Nittany Valley at the foot of the ridge was redesigned to avoid excavating contaminated rock from the same formation.
19:
1464:
884:
572:
1459:
1454:
1449:
1099:
221:
1033:
517:
512:
sandstone. The northwest slope of the ridge, where the rock layers are near vertical, exposes a series of rock layers, from summit to foot, or older to younger:
121:
1444:
1182:
1043:
930:
407:
276:
1076:
335:
1358:
331:
78:
841:
1439:
877:
299:
1149:
593:
647:
735:
760:
870:
810:
1008:
955:
915:
785:
1343:
1333:
621:
597:
233:
1424:
1013:
268:
181:
1373:
229:
489:
mountain are now exposed. Younger rocks from the outer layers of the arch are exposed on the west side of the ridge in the
1212:
1164:
965:
605:
323:
260:
225:
205:
1419:
1293:
1202:
1177:
256:
71:
1247:
1192:
1038:
710:
303:
252:
1429:
1393:
1227:
1134:
950:
945:
601:
351:
288:
264:
228:, and is the westernmost ridge in its section of the Ridge-and-Valley Appalachians. The ridge line separates the
1119:
970:
925:
378:
47:
1434:
1124:
1018:
339:
327:
501:
layers were tipped almost vertical on the side of the ancient mountain where Bald Eagle
Mountain now lies.
1323:
1277:
1237:
845:
609:
525:
403:
237:
169:
629:
1068:
521:
463:
429:
295:
284:
280:
1298:
1197:
1187:
902:
529:
470:
448:
1368:
1363:
1318:
1308:
1267:
545:
541:
537:
362:
1398:
1058:
1028:
1023:
1000:
739:
509:
490:
437:
241:
764:
1348:
1328:
1313:
1217:
1094:
1053:
533:
498:
411:
399:
373:. It is one of the best sites in the eastern United States for viewing the migration of the
817:
1383:
1272:
1252:
1129:
1104:
910:
685:
494:
415:
213:
176:
789:
668:
571:
where it crosses Bald Eagle
Mountain has been delayed since 2004 by complaints from the
1338:
1257:
1172:
1114:
1048:
990:
985:
960:
560:
482:
474:
343:
307:
245:
162:
1413:
1353:
1262:
1222:
1086:
980:
568:
556:
513:
393:
366:
347:
311:
217:
198:
43:
369:
along its slopes. This ridge is part of a chain of ridges that stretch southwest to
1388:
1242:
975:
935:
894:
374:
358:
209:
154:
477:
up with the underlying and overlying layers into the
Nittany Arch. The arch was a
1378:
1303:
1232:
1207:
1144:
1139:
940:
634:
613:
564:
1109:
426:
93:
80:
1154:
862:
617:
452:
433:
422:
419:
370:
319:
272:
714:
540:
Shriver chert, Mandata shale, Corriganville chert, New Creek limestone and
478:
445:
315:
486:
692:. Pennsylvania State University College of Earth and Mineral Sciences
576:
552:
61:
458:
36:
628:
457:
441:
201:
555:
veins, and when exposed to air and water, these minerals produce
287:, to the bend in the West Branch Susquehanna River just east of
866:
761:"Short Explanation of the Geological Structure of Pennsylvania"
318:
known as "Skytop". Most other major road crossings are through
381:
lies at the foot of this ridge between Julian and
Unionville.
384:
A mature oak and hickory forest covers Bald Eagle
Mountain.
637:
boulder fields on the mountainside in this view facing east
608:. The eastern end of the mountain is at far left, with the
786:"Description of the Geology of Centre County Pennsylvania"
493:, with the youngest across the valley at the foot of the
23:
Bald Eagle
Mountain in Lycoming County shown in May 2019
263:, and the ridge line forms part of the border between
291:, a distance of approximately 60 miles (97 km).
485:, where the oldest rock layers from deep within the
1286:
1163:
1085:
1067:
999:
901:
573:
Pennsylvania
Department of Environmental Protection
251:Bald Eagle Mountain lies in the central portion of
175:
161:
150:
109:
70:
60:
55:
29:
596:Bald Eagle Mountain, looking south from a hill in
398:Bald Eagle Mountain is in the western part of the
736:"Pennsylvania State Parks - Bald Eagle - PA DCNR"
508:The southeast slope of the ridge is underlaid by
816:. Pennsylvania Geological Survey. Archived from
302:Pikes are paved roads that cross the ridge near
481:-scale mountain that towered above what is now
673:. Philadelphia: Edward C. Biddle. p. 255.
330:. Other water gaps in the ridge are formed by
878:
8:
686:"Geological Report on the Skytop Road Cuts"
528:shale, siltstone, limestone, and dolomite,
524:shale, siltstone, sandstone, and mudstone,
128:
1465:Landforms of Lycoming County, Pennsylvania
885:
871:
863:
425:, the limbs of which consist of the older
26:
1460:Ridges of Huntingdon County, Pennsylvania
1455:Landforms of Clinton County, Pennsylvania
1450:Landforms of Centre County, Pennsylvania
354:near Bald Eagle Mountain's eastern end.
326:which passes through Curtin Gap east of
18:
659:
551:The Bald Eagle sandstone is laced with
684:Gold, David P. & Doden, Arnold G.
616:crosses it at the middle left and the
334:on the south edge of Milesburg and by
220:. It lies along the southeast side of
844:. www.centredaily.com. Archived from
212:, United States, running east of the
16:Mountain in central Pennsylvania, USA
7:
1445:Ridges of Blair County, Pennsylvania
648:List of mountains of the Alleghenies
350:crosses through a wind gap south of
314:which pass through the now enlarged
14:
462:Geologic cross section along the
357:Bald Eagle Ridge is popular with
585:
127:
120:
35:
811:"Explanation of Geologic Units"
1440:West Branch Susquehanna Valley
1044:Mount Pisgah (Bradford County)
259:, and the southern portion of
230:West Branch Susquehanna Valley
1:
1165:Ridge-and-Valley Appalachians
226:West Branch Susquehanna River
206:Ridge-and-Valley Appalachians
1359:Mount Pisgah (Carbon County)
690:Geosciences: Feature Article
418:ridges are part of the same
394:Mount Nittany § Geology
184:Jersey Shore (PA) Quadrangle
46:on Bald Eagle Mountain near
670:A Geography of Pennsylvania
440:(interbedded sandstone and
1481:
391:
255:, the southern portion of
66:2,112 ft (644 m)
620:from Hagermans Run above
575:about acidic runoff from
542:Ridgeley Member sandstone
114:
34:
379:Ridge Soaring Gliderport
193:– once known locally as
141:Location in Pennsylvania
48:Lock Haven, Pennsylvania
711:"The Conservation Fund"
1425:Ridges of Pennsylvania
1324:Conococheague Mountain
638:
466:
24:
1278:Williamsburg Mountain
1238:Nesquehoning Mountain
632:
559:, contaminating both
526:Wills Creek Formation
520:shale and limestone,
518:Mifflintown Formation
516:sandstone and shale,
461:
404:Appalachian Mountains
170:Appalachian Mountains
94:41.12667°N 77.35111°W
22:
1069:Blue Ridge Mountains
717:on November 20, 2008
667:Trego, C.B. (1843).
522:Bloomsburg Formation
464:Little Juniata River
430:Bald Eagle Formation
410:and the neighboring
281:Little Juniata River
1420:Allegheny Mountains
1299:Buckingham Mountain
1198:Big Savage Mountain
1188:Bear Pond Mountains
1009:Blue Ridge Mountain
921:Bald Eagle Mountain
903:Allegheny Mountains
530:Tonoloway Formation
471:Alleghanian orogeny
449:Tuscarora Formation
271:. It runs from the
191:Bald Eagle Mountain
135:Bald Eagle Mountain
99:41.12667; -77.35111
90: /
30:Bald Eagle Mountain
1369:Osterhout Mountain
1364:Nescopeck Mountain
1319:Conewago Mountains
1309:Catawissa Mountain
1268:Tuscarora Mountain
1014:Camelback Mountain
916:Allegheny Mountain
742:on 12 January 2008
639:
622:South Williamsport
598:Loyalsock Township
567:. Construction of
548:calcareous shale.
546:Onondaga Formation
538:Old Port Formation
467:
56:Highest point
42:A Scimitar glider
25:
1430:Bald Eagle Valley
1407:
1406:
1399:Watchung Outliers
1344:McCauley Mountain
1334:Haystack Mountain
1059:Red Rock Mountain
1029:Forkston Mountain
1024:Endless Mountains
1001:Allegheny Plateau
823:on April 22, 2003
510:Juniata Formation
491:Bald Eagle Valley
438:Juniata Formation
269:Huntingdon County
242:Bald Eagle Valley
224:and south of the
216:and northwest of
188:
187:
50:
1472:
1349:Moosic Mountains
1329:Haycock Mountain
1314:Central Mountain
1218:Dunning Mountain
1095:Applebutter Hill
1054:Pocono Mountains
887:
880:
873:
864:
857:
856:
854:
853:
838:
832:
831:
829:
828:
822:
815:
807:
801:
800:
798:
797:
788:. Archived from
782:
776:
775:
773:
772:
763:. Archived from
757:
751:
750:
748:
747:
738:. Archived from
732:
726:
725:
723:
722:
713:. Archived from
707:
701:
700:
698:
697:
681:
675:
674:
664:
624:at middle right.
589:
534:Keyser Formation
499:sedimentary rock
412:Nittany Mountain
402:province of the
400:Ridge and Valley
222:Bald Eagle Creek
165:
131:
130:
124:
105:
104:
102:
101:
100:
95:
91:
88:
87:
86:
83:
41:
39:
27:
1480:
1479:
1475:
1474:
1473:
1471:
1470:
1469:
1410:
1409:
1408:
1403:
1384:Pisgah Mountain
1374:Peters Mountain
1282:
1273:Tussey Mountain
1253:Savage Mountain
1159:
1130:Lehigh Mountain
1105:Christines Hill
1081:
1063:
1034:Miller Mountain
995:
911:Allegheny Front
897:
891:
861:
860:
851:
849:
840:
839:
835:
826:
824:
820:
813:
809:
808:
804:
795:
793:
784:
783:
779:
770:
768:
759:
758:
754:
745:
743:
734:
733:
729:
720:
718:
709:
708:
704:
695:
693:
683:
682:
678:
666:
665:
661:
656:
644:
633:Gray areas are
627:
626:
625:
606:Lycoming County
595:
590:
495:Allegheny Front
473:, these layers
444:), and younger
416:Tussey Mountain
396:
390:
261:Lycoming County
238:White Deer Hole
214:Allegheny Front
163:
146:
145:
144:
143:
142:
139:
138:
137:
136:
132:
98:
96:
92:
89:
84:
81:
79:
77:
76:
51:
17:
12:
11:
5:
1478:
1476:
1468:
1467:
1462:
1457:
1452:
1447:
1442:
1437:
1435:Nittany Valley
1432:
1427:
1422:
1412:
1411:
1405:
1404:
1402:
1401:
1396:
1391:
1386:
1381:
1376:
1371:
1366:
1361:
1356:
1351:
1346:
1341:
1339:Jacks Mountain
1336:
1331:
1326:
1321:
1316:
1311:
1306:
1301:
1296:
1290:
1288:
1284:
1283:
1281:
1280:
1275:
1270:
1265:
1260:
1258:Sharp Mountain
1255:
1250:
1245:
1240:
1235:
1230:
1225:
1220:
1215:
1213:Cross Mountain
1210:
1205:
1200:
1195:
1190:
1185:
1180:
1175:
1173:Bake Oven Knob
1169:
1167:
1161:
1160:
1158:
1157:
1152:
1150:South Mountain
1147:
1142:
1137:
1132:
1127:
1122:
1117:
1115:Hexenkopf Hill
1112:
1107:
1102:
1097:
1091:
1089:
1083:
1082:
1080:
1079:
1077:South Mountain
1073:
1071:
1065:
1064:
1062:
1061:
1056:
1051:
1049:Penobscot Knob
1046:
1041:
1036:
1031:
1026:
1021:
1016:
1011:
1005:
1003:
997:
996:
994:
993:
991:Wills Mountain
988:
986:Sugarloaf Knob
983:
978:
973:
968:
966:North Mountain
963:
961:Negro Mountain
958:
956:Chestnut Ridge
953:
948:
943:
938:
933:
931:Brush Mountain
928:
923:
918:
913:
907:
905:
899:
898:
892:
890:
889:
882:
875:
867:
859:
858:
833:
802:
777:
752:
727:
702:
676:
658:
657:
655:
652:
651:
650:
643:
640:
592:
591:
584:
583:
582:
561:surface runoff
483:Nittany Valley
408:Brush Mountain
389:
386:
344:U.S. Route 220
308:U.S. Route 322
277:Brush Mountain
257:Clinton County
246:Nittany Valley
195:Muncy Mountain
186:
185:
179:
173:
172:
167:
159:
158:
152:
148:
147:
140:
134:
133:
126:
125:
119:
118:
117:
116:
115:
112:
111:
107:
106:
74:
68:
67:
64:
58:
57:
53:
52:
40:
32:
31:
15:
13:
10:
9:
6:
4:
3:
2:
1477:
1466:
1463:
1461:
1458:
1456:
1453:
1451:
1448:
1446:
1443:
1441:
1438:
1436:
1433:
1431:
1428:
1426:
1423:
1421:
1418:
1417:
1415:
1400:
1397:
1395:
1392:
1390:
1387:
1385:
1382:
1380:
1377:
1375:
1372:
1370:
1367:
1365:
1362:
1360:
1357:
1355:
1354:Mount Nittany
1352:
1350:
1347:
1345:
1342:
1340:
1337:
1335:
1332:
1330:
1327:
1325:
1322:
1320:
1317:
1315:
1312:
1310:
1307:
1305:
1302:
1300:
1297:
1295:
1294:Buck Mountain
1292:
1291:
1289:
1285:
1279:
1276:
1274:
1271:
1269:
1266:
1264:
1263:Sideling Hill
1261:
1259:
1256:
1254:
1251:
1249:
1246:
1244:
1241:
1239:
1236:
1234:
1231:
1229:
1226:
1224:
1223:Hawk Mountain
1221:
1219:
1216:
1214:
1211:
1209:
1206:
1204:
1203:Blue Mountain
1201:
1199:
1196:
1194:
1191:
1189:
1186:
1184:
1183:Bear Mountain
1181:
1179:
1178:Bald Mountain
1176:
1174:
1171:
1170:
1168:
1166:
1162:
1156:
1153:
1151:
1148:
1146:
1143:
1141:
1138:
1136:
1133:
1131:
1128:
1126:
1123:
1121:
1118:
1116:
1113:
1111:
1108:
1106:
1103:
1101:
1100:Chestnut Hill
1098:
1096:
1093:
1092:
1090:
1088:
1087:Reading Prong
1084:
1078:
1075:
1074:
1072:
1070:
1066:
1060:
1057:
1055:
1052:
1050:
1047:
1045:
1042:
1040:
1037:
1035:
1032:
1030:
1027:
1025:
1022:
1020:
1017:
1015:
1012:
1010:
1007:
1006:
1004:
1002:
998:
992:
989:
987:
984:
982:
981:Schaefer Head
979:
977:
974:
972:
969:
967:
964:
962:
959:
957:
954:
952:
949:
947:
944:
942:
939:
937:
934:
932:
929:
927:
924:
922:
919:
917:
914:
912:
909:
908:
906:
904:
900:
896:
893:Mountains of
888:
883:
881:
876:
874:
869:
868:
865:
848:on 2006-12-19
847:
843:
837:
834:
819:
812:
806:
803:
792:on 2006-12-09
791:
787:
781:
778:
767:on 2007-04-20
766:
762:
756:
753:
741:
737:
731:
728:
716:
712:
706:
703:
691:
687:
680:
677:
672:
671:
663:
660:
653:
649:
646:
645:
641:
636:
631:
623:
619:
615:
611:
607:
603:
600:just east of
599:
594:
588:
581:
578:
574:
570:
569:Interstate 99
566:
562:
558:
557:sulfuric acid
554:
549:
547:
543:
539:
535:
531:
527:
523:
519:
515:
514:Clinton Group
511:
506:
502:
500:
496:
492:
488:
484:
480:
476:
472:
465:
460:
456:
454:
450:
447:
443:
439:
435:
431:
428:
424:
421:
417:
413:
409:
405:
401:
395:
387:
385:
382:
380:
376:
372:
368:
367:ridge soaring
364:
360:
359:soaring birds
355:
353:
349:
348:U.S. Route 15
345:
341:
337:
336:Fishing Creek
333:
329:
325:
324:Interstate 80
321:
317:
313:
312:Interstate 99
309:
306:, along with
305:
304:State College
301:
297:
292:
290:
286:
282:
278:
274:
270:
266:
262:
258:
254:
253:Centre County
249:
247:
243:
240:valleys, and
239:
235:
231:
227:
223:
219:
218:Mount Nittany
215:
211:
207:
203:
200:
199:stratigraphic
196:
192:
183:
180:
178:
174:
171:
168:
166:
160:
156:
153:
149:
123:
113:
108:
103:
75:
73:
69:
65:
63:
59:
54:
49:
45:
44:ridge soaring
38:
33:
28:
21:
1389:Sidneys Knob
1248:The Pinnacle
1243:Parnell Knob
1193:Big Mountain
1039:Mount Ararat
976:Ritchey Knob
936:Herman Point
920:
895:Pennsylvania
850:. Retrieved
846:the original
836:
825:. Retrieved
818:the original
805:
794:. Retrieved
790:the original
780:
769:. Retrieved
765:the original
755:
744:. Retrieved
740:the original
730:
719:. Retrieved
715:the original
705:
694:. Retrieved
689:
679:
669:
662:
602:Williamsport
577:pyritic rock
550:
507:
503:
468:
451:(dominantly
397:
383:
375:golden eagle
356:
352:Williamsport
332:Spring Creek
322:, including
293:
289:Williamsport
275:formed with
265:Blair County
250:
210:Pennsylvania
194:
190:
189:
164:Parent range
155:Pennsylvania
1394:Turkey Hill
1379:Pimple Hill
1304:Butler Knob
1233:Mount Minsi
1228:Martin Hill
1208:Clarks Knob
1145:Saucon Hill
1140:Pektor Hill
1135:Morgan Hill
951:Mount Davis
946:Laurel Hill
941:Kinton Knob
635:periglacial
614:US Route 15
565:groundwater
536:limestone,
532:limestone,
469:During the
208:of central
97: /
72:Coordinates
1414:Categories
1110:Focht Hill
852:2008-01-26
827:2008-01-26
796:2009-04-12
771:2009-04-12
746:2008-01-26
721:2009-04-12
696:2008-01-26
654:References
427:Ordovician
392:See also:
346:crosses).
320:water gaps
300:Unionville
85:77°21′04″W
82:41°07′36″N
1155:Swoveberg
1120:Kirchberg
971:Pine Knob
926:Blue Knob
618:water gap
479:Himalayan
453:quartzite
434:sandstone
423:anticline
420:Paleozoic
371:Tennessee
340:Mill Hall
328:Milesburg
273:water gap
234:Nippenose
232:from the
110:Geography
62:Elevation
1125:Kohlberg
1019:Elk Hill
642:See also
610:wind gap
497:. These
446:Silurian
316:wind gap
177:Topo map
151:Location
388:Geology
365:pilots
342:(where
279:by the
204:in the
197:– is a
1287:Others
842:"I-99"
612:where
553:pyrite
544:, and
487:eroded
475:folded
377:. The
363:glider
296:Julian
285:Tyrone
157:, U.S.
821:(PDF)
814:(PDF)
442:shale
244:from
202:ridge
563:and
414:and
361:and
310:and
298:and
294:The
267:and
236:and
182:USGS
604:in
455:).
436:),
338:at
283:at
1416::
688:.
406:.
248:.
886:e
879:t
872:v
855:.
830:.
799:.
774:.
749:.
724:.
699:.
432:(
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