River Saraswati, as described in scriptures.

River Saraswati has been the biggest issue of discussion with regards to it's existence. There is a confusion whether it was a river or a Hindu goddess. The answer is, perhaps both. But most importantly, it was the biggest and widest river in the Indian subcontinent.

The Aryan Invasion theorists say that river Saraswati is a myth and she was just a goddess of knowledge. Well, I would counter that by one single logic- There is a goddess called Kali and also a river called Kali in Karnataka. So does that river become mythical ?
It has been a common practice to name objects, whether rivers, mountains or lakes, on the names of popular gods and goddesses. The sole reason why our planets got their names as Venus or Mars from the Greek and Roman gods. Plus, the satellite images of Saraswati are quite clearly showing the existence of a huge channel of an extinct river which flows through the heart of Rajasthan.

The course of Saraswati photographed by satellites.
A huge course in the heart of a desert... !!!!

 We will discuss the geography and logic behind the existence of Saraswati later on. For now, we are concerned with different references to Saraswati in ancient scriptures.
We will traverse through scriptures in their chronological existence through history viz Rigveda and Atharvaveda ---> Yajurveda ---> Ramayana --->Mahabharata and Puranas ---> Brahmanas

Saraswati in Rigveda- 

एकाचेतत्सरस्वती नदीनां शुचिर्यती गिरिभ्य आ समुद्रात्। रायश्चेतन्ती भुवनस्य भूरेर्घृतं पयो दुदुहे नाहुषाय॥ - 

RV 7.95.2

Pure in her course from the mountains to the oceans, Saraswati river bestows milk and butter to Nahusha.

अम्बितमे नदीतमे देवितमे सरस्वति। अप्रशस्ता इव स्मसि प्रशस्तिमम्ब नस्कृधि ||

RV 2.41.16

Best of mothers, best of rivers, best of goddesses Sarsawati, we are untrained and ignorant. Give us knowledge and wisdom.

इयं शुष्मेभिर्बिसखा इवारुजत्सानु गिरीणां तविषेभिरूर्मिभिः।

पारावतघ्नीमवसे सुवृक्तिभिः सरस्वतीमा विवासेम धीतिभिः॥

RV 6.61.2

O Saraswati, your mighty currents break the mountains as easily as lotus stems. Let us invite with holy hymns and songs.

यस्या अनन्तो अह्रुतस्त्वेषश्चरिष्णुरर्णवः।अमश्चरति रोरुवत्॥

RV 6.61.8

Whose limitless, unbroken flow, swift moving with rapid rush comes forward with a roar. 

आ यत्साकं यशसो वावशानाः सरस्वती सप्तथी सिन्धुमाता।

याः सुष्वयन्त सुदुघाः सुधारा अभि स्वेन पयसा पीप्यानाः॥

RV 7.36.6

May the glorious seventh stream Saraswati, mother of Sindhu charged with large volume of water flow vigorously and give milk and water.

This was a short description of Saraswati in the Rigveda. In totality, Saraswati has been mentioned 71 times throughout the Rigveda.

Saraswati in Atharvaveda- 

देवा इमं मधूनां संयुतं यवं सरस्वत्या मधि मनावकर्क्रियुः| इन्द्र आसित सिरपतिः शतक्रतुः किनश आसन मरुतः सुदानवः ||

AV 6.30.1

God bestowed the people living on the banks of Saraswati with sweet and juicy barley, where the Maruts become the farmers and Indra, the lord of agriculture.

Saraswati is mentioned almost 35 times throughout Atharvaveda, sometimes as a river and sometimes as a goddess.
Yajurveda ans Samaveda also mention Saraswati river.

Saraswati in Ramayana- 

सरस्वतीम् च गङ्गाम् च उग्मेन प्रतिपद्य च |
उत्तरम् वीरमत्स्यानाम् भारुण्डम् प्राविशद्वनम् ||

Valmiki Ramayana 2.71.2

Arriving at the confluence of Saraswati and Ganga rivers, Bharata entered the woods of Bharmuda, the north of Viramatsaya region.

Saraswati is mentioned almost 6 times in Valmiki Ramayana. The above reference shows that the river did exist during Ram's times.

Saraswati in Mahabharata- 

Balrama had gone on a 42 day pilgrimage which is properly described in the Mahabharata. Right from the origin of Saraswati to it's disappearance is properly mentioned.

परभवं च सरस्वत्याः पलक्षप्रस्रवणं बलः |

     संप्राप्तः कारपचनं तीर्थप्रवरम उत्तमम ||

Mbh 9.53.11

While ascending the Himalaya, Balrama came to Plaksha Prashravana, the origin of Saraswati from where he went to Karpachanam ( Origin of Yamuna). 

सरस्वती पुण्यवहा हरदिनी वनमालिनी |

      समुद्रगा महावेगा यमुना यत्र पाण्डव ||

Mbh 3.88.2

The holy flow of Saraswati [ ...] meets the sea with rapid flow. 

ततॊ विनशनं गच्छेन नियतॊ नियताशनः गच्छत्य अन्तर्हिता यत्र मरु पृष्ठे 

सरस्वती चमसे च शिवॊद्भेदे नागॊद्भेदे च दृश्यते ||

Mbh 3.80.118

The Saraswati disappears in the desert at Vinshana and reappears at Chamasa, Shivodbheda ans Nagodbheda. 

Mahabharata (3.83) mentions the location of Kurukshetra as lying to the south of Saraswati and north of Drishadvati, clearly indicating the geography of Haryana. Similar thing is mentioned about Brahmavarta, the kingdom of Swayambhuva Manu in Bhagvata Purana and Manusmriti (3.17)

Mahabharata also mentions a number of lakes like Bindusar, Brahmasar, Jyotisar, etc which the Saraswati occupies. A clear cut indication that Saraswati had become a small river then and was only occupying lakes.

Since the geography of Mahabharata revolves around the Krur kingdom from where the Saraswati flowed, Saraswati is mentioned 235 times in Mahabharata. 

Saraswati in Puranas- 

 Vamana Purana (32. 1-4) describes the origin of Saraswati, as told by rishi Markandeya. It tells about the Plaksha (Pipal) tree from where the Saraswati originates from where it flows westward and occupies a lake called Sannihita. 

Apart from these, Saraswati and it's origin at Plaksha and vanishing at Vinshana has been mentioned in Bhagvata, Vishnu, Skanda, Vayu Puranas.

The flow of Saraswati, photographed from Bheem Pul in the Himalayas.
This river today is called Ghaggar- Hakra  known to be the remnant of the mighty Saraswati.

Saraswati in Brahmanas- 

Tandya Brahmana is the most useful for this prupose. (25.10.11) mentions Saraswati to be sluggish (शिथीलभूत ) and following a meandering course ( वक्रोपेतभूत ).

(25.10.12) mentions Saraswati to be drifting westward ( प्रत्यन्मुखी )

The same info of Saraswati originating at Plaksha and vanishing at Vinshana is mentioned and the distance between the two is said to be 44 Ashvins. From the info I gathered from the article of D.S Chauhan, this distance is about 2600 KMs. So if Vinshana has to be in Gujarat, Plaksha has to be in the Himalayas.

CONCLUSION-

From the above verses quoted, any keen observer will come to know the trend of Saraswati's references from a huge river with a rapid flow to a small river which was vanishing in desert.

The chronological order of scriptures Rigveda and Atharvaveda ---> Yajurveda --->; Ramayana -->;Mahabharata and Puranas --->; Brahmanas tells us the diminishing nature of the Saraswati from a mighty river in Rigvedic times to a small river about to vanish during the Puranic times. 

Saraswati was NOT a myth. It was an actual river on whose banks majority of the Harappan sites have been found. She is also a goddess of knowledge and also an extinct river. Only if secular historians understood that...........